Quality of service QoS parameter processing method and network element, system, and storage medium

ABSTRACT

A quality of service (QoS) parameter processing method and a system, where the method includes a session management function device obtaining a core network (CN) packet delay budget (PDB) between a first access network device and a first user plane function device, and sending the CN PDB to the first access network device via a context update response message, where the first access network device is a target access network device serving a terminal device after a handover. After receiving the CN PDB, the first access network device determines an access network (AN) PDB between the terminal device and the first access network device based on the CN PDB and an end-to-end PDB between the terminal device and the first user plane function device, and then schedules an air interface resource between the terminal device and the first access network device based on the AN PDB.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Patent ApplicationNo. PCT/CN2018/121443 filed on Dec. 17, 2018, which claims priority toChinese Patent Application No. 201810152278.9 filed on Feb. 14, 2018 andto Chinese Patent Application No. 201810892877.4 filed on Aug. 7, 2018.The disclosures of the aforementioned applications are herebyincorporated by reference in their entireties.

TECHNICAL FIELD

This application relates to the field of communications technologies,and in particular, to a quality of service (QoS) parameter processingmethod and network element, a system, and a storage medium.

BACKGROUND

In a conventional 3rd Generation Partnership Project (3GPP) network, anaccess network (AN) device and a user plane function (UPF) networkelement schedule and forward a data packet based on a priority of thedata packet. This may cause a large end-to-end latency and jitter (alatency variation value) of the data packet. Therefore, a mechanism offorwarding a data packet based on a priority cannot satisfy arequirement of a deterministic service, and the data packet cannot beprecisely scheduled in other approaches, deteriorating user experience.

SUMMARY

This application provides a QoS parameter processing method and networkelement, a system, and a storage medium, to improve data packetscheduling accuracy and improve user experience.

According to a first aspect, this application provides a QoS parameterprocessing method, and the method includes obtaining, by a control planenetwork element, a first QoS parameter between a terminal device and aUPF network element, and obtaining, by the control plane networkelement, capability information of a first network domain, determining asecond QoS parameter of the first network domain based on the capabilityinformation of the first network domain and the first QoS parameter, andsending first information of the second QoS parameter to the firstnetwork domain. The first network domain includes at least one of aradio access network (RAN), a backhaul network, and a UPF networkelement. The backhaul network may also be referred to as a transmissionnetwork. For example, the second QoS parameter includes at least one ofa latency parameter, a jitter parameter, and a reliability parameter.

According to the method, the control plane network element determinesthe second QoS parameter of the first network domain (that is,determines a QoS parameter of at least one network domain) based on thecapability information of the first network domain and the first QoSparameter, to be specific, separately assigns a proper QoS parameter toeach network domain, and then separately delivers the QoS parameter toeach network domain, ensuring that the QoS parameter obtained by eachnetwork domain is a QoS parameter of the corresponding network domain.Compared with an existing mechanism in which each network domain canschedule a data packet based on only an end-to-end indicator, in thisembodiment of this application, a communications apparatus in eachnetwork domain can perform precise scheduling based on the QoS parameterof the corresponding network domain, ensuring deterministic transmissionand improving user experience. In addition, because the QoS parameter ofeach network domain may be dynamically assigned, resource utilization ofa mobile network can be improved.

For example, a procedure in which the control plane network elementdetermines the second QoS parameter of the first network domain anddelivers the first information may occur in a procedure in a sessionestablishment phase, or may occur in procedure in a handover phase. Inaddition, the determining of the second QoS parameter may refer to thefirst division of the QoS parameter, or may be subsequent re-division ofthe QoS parameter.

Based on the first aspect, in a first implementation, when the firstnetwork domain includes the RAN or the UPF network element, obtaining,by the control plane network element, capability information of a firstnetwork domain includes sending, by the control plane network element, atransmit frequency and a size of a data packet to the first networkdomain, and receiving the capability information of the first networkdomain from the first network domain, where the capability informationof the first network domain is associated with the transmit frequencyand the size of the data packet.

Based on the first aspect or the first implementation of the firstaspect, in a second implementation, when the first network domainincludes the RAN or the UPF network element, the first informationincludes a correspondence between a flow identifier and the second QoSparameter, and the flow identifier is used to identify a QoS flowbetween the terminal device and the UPF network element.

Based on the first aspect, in a third implementation, when the firstnetwork domain includes the backhaul network, obtaining, by the controlplane network element, capability information of a first network domainincludes receiving, by the control plane network element, from a networkmanagement network element, capability information of the backhaulnetwork, or obtaining, by the control plane network element, from a datamanagement network element, capability information of the backhaulnetwork.

The capability information of the backhaul network includes a streamidentifier of a service flow in the backhaul network, a quantity ofavailable service flows, and a QoS parameter of the service flow. Forexample, the QoS parameters of the service flow may include a bandwidthparameter and reliability of the service flow.

Based on the first aspect or the third implementation, in a fourthimplementation, when the first network domain includes the backhaulnetwork, the first information may include a correspondence between aflow identifier and a stream identifier, the flow identifier is used toidentify a QoS flow between the terminal and the UPF network element,and the stream identifier is used to identify a stream that is in thebackhaul network and that satisfies the second QoS parameter.

The correspondence between a flow identifier and a stream identifier canbe used for forwarding and resource scheduling of a downlink data packetwhen the UPF network element sends the downlink data packet to theaccess network device, or can be used for forwarding and resourcescheduling of an uplink data packet when the access network device sendsthe uplink data packet to the UPF network element.

Based on any one of the first aspect or the first to the fourthimplementations of the first aspect, in a fifth implementation, themethod further includes obtaining, by the control plane network element,subscription data of the terminal device. For example, the subscriptiondata of the terminal device is data corresponding to a servicesubscribed to by the terminal device, and may include a QoS parameter,account information, a service type, a service level, and the like thatcorrespond to the service subscribed to by the terminal device.Determining a second QoS parameter of the first network domain based onthe capability information of the first network domain and the first QoSparameter includes, when the subscription data includes the secondinformation used to indicate that the service of the terminal deviceincludes a deterministic service, that is, the control plane networkelement may determine that the service of the terminal device includesthe deterministic service, a corresponding QoS parameter needs to beassigned to the first network domain in which the terminal device islocated. Therefore, the control plane network element may determine thesecond QoS parameter of the first network domain based on the capabilityinformation of the first network domain and the first QoS parameter.

It can be learned that, whether the control plane network element needsto divide a first QoS parameter corresponding to a service can bedetermined using an explicit indication in the subscription data. Inthis way, the first QoS parameter can be divided pertinently, reducingan unnecessary QoS parameter division procedure.

Based on the fifth implementation of the first aspect, in a sixthimplementation, the second information includes a jitter parameter. Ifthe subscription data includes the jitter parameter, the deterministicservice of the terminal device has a relatively high requirement ontransmission stability, and the control plane network element needs tospecially assign a corresponding second QoS parameter to the firstnetwork domain in which the terminal device is located. In this way,stability of the deterministic service of the terminal device can beensured subsequently.

Based on any one of the first aspect or the first to the sixthimplementations of the first aspect, in a seventh implementation,determining a second QoS parameter of the first network domain based onthe capability information of the first network domain and the first QoSparameter includes determining, by the control plane network element,the second QoS parameter for the first network domain based on thecapability information of the first network domain, the first QoSparameter, and a priority of the first network domain. For example, acapability of the RAN may be preferentially satisfied such that aminimum quantity of resources is reserved for the RAN. It can be learnedthat, according to this division principle, a resource in the firstnetwork domain can be more properly used, and subsequent QoS parameterreassignment caused by reasons such as improper allocation of a resourceand terminal device handover is reduced, reducing an unnecessaryprocedure of the control plane network element.

According to a second aspect, this application provides a QoS parameterprocessing method. The method may be used for a communications apparatusin a first network domain. The method may include sending, by thecommunications apparatus in the first network domain, capabilityinformation of the first network domain to a control plane networkelement, and receiving, from the control plane network element, firstinformation of the QoS parameter of the first network domain. Thecapability information of the first network domain is used to determinea QoS parameter of the first network domain, and the first networkdomain includes a RAN or a UPF network element.

According to the method, the communications apparatus in the firstnetwork domain provides the capability information of the first networkdomain for the control plane network element such that the control planenetwork element can accurately determine the QoS parameter of the firstnetwork domain, and the communications apparatus of the first networkdomain obtains, from the control plane network element, the QoSparameter of the first network domain. Therefore, a communicationsapparatus in a network domain can perform precise scheduling based on aQoS parameter of this network domain, ensuring the deterministictransmission and improving user experience. In addition, resourceutilization of a mobile network can be improved.

Based on the second aspect, in a first implementation, the communicationapparatus may further report the capability information of the firstnetwork domain to the control plane network element, which may includeone of the following manners periodically reporting, by thecommunications apparatus, the capability information of the firstnetwork domain to the control plane network element, or after receivinga request message from the control plane network element, feeding back,by the communications apparatus, the capability information of the firstnetwork domain to the control plane network element. For example, afterreceiving a transmit frequency and a size of a data packet from thecontrol plane network element, the communications apparatus obtains thecapability information of the first network domain based on the transmitfrequency and the size of the data packet, and then feeds back thecapability information to the control plane network element.

It can be learned that the capability information of the first networkdomain is dynamically fed back to the control plane network element suchthat the control plane network element can more precisely and moreproperly divide the QoS parameter between a terminal device and the UPFnetwork element, ensuring the stability of the deterministic service ofthe terminal device.

Based on the second aspect or the first implementation of the secondaspect, in a second implementation, the first information may include acorrespondence between a flow identifier and the QoS parameter, and theflow identifier is used to identify a QoS flow between the terminaldevice and the UPF network element. For example, when the first networkdomain includes the RAN, the first information includes a correspondencebetween the flow identifier and a QoS parameter of the RAN. When thefirst network domain includes the UPF network element, the firstinformation includes a correspondence between the flow identifier and aQoS parameter of the UPF network element.

In this way, after an access network device in the RAN and the UPFnetwork element receive QoS parameters of respective domains, the accessdevice in the RAN can find, based on the correspondence between the flowidentifier and a QoS parameters of the RAN, a QoS parametercorresponding to the data packet, and forward an uplink/downlink datapacket based on the QoS parameter, and the UPF network element can find,based on the correspondence between the flow identifier and a QoSparameter of the UPF network element, a QoS parameter corresponding tothe data packet, and forward an uplink/downlink data packet based on theQoS parameter.

The following separately describes, based on a type of the first networkdomain, procedures for forwarding the uplink/downlink data packet by theaccess network device and the UPF network element.

Based on the second implementation of the second aspect, in a thirdimplementation, when the first network domain includes the RAN, thecommunications apparatus is a first access network device in the RAN.The method further includes at least one of receiving, by the firstaccess network device, a downlink data packet from the UPF networkelement, where the downlink data packet includes a first flowidentifier, and sending, by the first access network device, thedownlink data packet to the terminal device based on a QoS parameterthat is in the first information and that corresponds to the first flowidentifier, or receiving, by the first access network device, an uplinkdata packet from the terminal device, where the uplink data packetincludes a second flow identifier, and sending, by the first accessnetwork device through a backhaul network, the uplink data packet to theUPF network element based on a QoS parameter that is in the firstinformation and that corresponds to the second flow identifier.

Based on the third implementation of the second aspect, in a fourthimplementation, the first access network device may further receive,from the control plane network element, a correspondence between thesecond flow identifier and a stream identifier of a first stream.Correspondingly, when forwarding an uplink data packet, the first accessnetwork device may send, based on the correspondence between the secondflow identifier and the stream identifier of the first stream, theuplink data packet to the UPF network element using the first stream inthe backhaul network.

It can be learned that the first access network device can implementprecise resource scheduling and data packet forwarding operations basedon a correspondence between a flow identifier and a stream identifier,ensuring running of the deterministic service of the terminal device.

Based on any one of the second aspect or the first and the secondimplementations of the second aspect, in a fifth implementation, whenthe first network domain includes the UPF network element, thecommunications apparatus is the UPF network element, and the UPF networkelement may further forward the uplink/downlink data packet based on anassigned QoS parameter. The method further includes at least one of thefollowing receiving, by the UPF network element, a downlink data packetfrom an application server, obtaining a first flow identifier includedin the downlink data packet, and sending, through the backhaul network,the downlink data packet to a first access network device based on a QoSparameter that is in the first information and that corresponds to thefirst flow identifier, or receiving, by the UPF network element, anuplink data packet from a first access network device, obtaining asecond flow identifier included the uplink data packet, and sending theuplink data packet to an application server based on a QoS parameterthat is in the first information and that corresponds to the second flowidentifier.

Based on any implementation in the fifth implementation of the secondaspect, in a sixth implementation, the UPF network element may furtherreceive, from the control plane network element, a correspondencebetween the first flow identifier and a stream identifier of a secondstream, when forwarding the downlink data packet, the UPF networkelement may send the downlink data packet to the access network devicebased on the correspondence between the first flow identifier and thestream identifier of the second stream using the second stream in thebackhaul network, after encapsulating the stream identifier of thesecond stream into the data packet.

It can be learned that the UPF network element can implement the preciseresource scheduling and data packet forwarding operations based on thecorrespondence between a flow identifier and a stream identifier,ensuring running of the deterministic service of the terminal device.

According to a third aspect, this application provides a QoS parameterprocessing method, and the method includes obtaining, by a sessionmanagement function network element, from a data management networkelement, subscription data of a terminal device, and when thesubscription data includes information used to indicate that a serviceof the terminal device includes a deterministic service, sending, by thesession management function network element, a request message to acontrol plane network element, where the request message is used torequest to determine a QoS parameter of a first network domain, and thefirst network domain includes at least one of a RAN, a backhaul network,and a UPF network element. According to the method, the sessionmanagement function network element obtains the subscription data fromthe data management network element, determines, based on thesubscription data, whether the terminal device has the deterministicservice, and then determines whether to send, to the control planenetwork element, the request message for determining the QoS parameterof the first network domain. In this way, work load of the control planenetwork element can be reduced, and a work division mechanism can alsobe optimized.

Based on the third aspect, in a first implementation of the thirdaspect, the method further includes obtaining, by the session managementfunction network element, from the data management network element,capability information of the backhaul network, or receiving, by thesession management function network element, from a network managementnetwork element, capability information of the backhaul network.

According to a fourth aspect, this application provides a networkmanagement method, and the method includes sending, by a networkmanagement network element, a configuration request to a backhaulnetwork configuration network element, where the configuration requestis used to request to configure capability information of a backhaulnetwork, and receiving, by the network management network element, fromthe backhaul network configuration network element, the capabilityinformation of the backhaul network, and sending the capabilityinformation of the backhaul network to a data management networkelement. According to the method, interaction between the networkmanagement network element, the backhaul network configuration networkelement, and the data management network element ensures that thecapability information of the backhaul network can be transmitted to thedata management network element, and subsequently a control planenetwork element uses the capability information of the backhaul networkas a basis for determining a QoS parameter of each network domain.

According to a fifth aspect, this application provides a networkmanagement method, and the method includes receiving, by a backhaulnetwork configuration network element, a configuration request from anetwork management network element, configuring capability informationof a backhaul network based on the configuration request, and sendingthe capability information of the backhaul network to the networkmanagement network element. According to the method, after the backhaulnetwork configuration network element receives the configuration requestfrom the network management network element, the backhaul networkconfiguration network element interacts with the network managementnetwork element such that the capability information of the backhaulnetwork can be transmitted to the network management network element,and the control plane network element subsequently uses the capabilityinformation of the backhaul network, obtained from the data managementnetwork element, as a basis for determining a QoS parameter of eachnetwork domain.

Based on the fifth aspect, in a first implementation of the fifthaspect, the configuration request may include an expected value of a QoSparameter of a first network domain, an Internet Protocol (IP) addressof an access network device, and an IP address of a UPF network element.

According to a sixth aspect, this application provides a control planenetwork element for processing a QoS parameter, and the control planenetwork element has a function of implementing the corresponding QoSparameter processing method according to the first aspect. The functionmay be implemented by hardware, or implemented by hardware executingcorresponding software. The hardware or software includes one or moremodules corresponding to the function. The module may be software and/orhardware.

According to a seventh aspect, this application provides acommunications apparatus for processing a QoS parameter, and thecommunications apparatus has a function of implementing thecorresponding QoS parameter processing method according to the secondaspect. The function may be implemented by hardware, or implemented byhardware executing corresponding software. The hardware or softwareincludes one or more modules corresponding to the function. The modulemay be software and/or hardware.

According to an eighth aspect, this application provides a sessionmanagement function network element, and the session management functionnetwork element has a function of implementing the corresponding QoSparameter processing method according to the third aspect. The functionmay be implemented by hardware, or implemented by hardware executingcorresponding software. The hardware or software includes one or moremodules corresponding to the function. The module may be software and/orhardware.

According to a ninth aspect, this application provides a networkmanagement network element, and the network management network elementhas a function of implementing the corresponding network managementmethod according to the fourth aspect. The function may be implementedby hardware, or implemented by hardware executing correspondingsoftware. The hardware or software includes one or more modulescorresponding to the function. The module may be software and/orhardware.

According to a tenth aspect, this application provides a networkconfiguration network element for managing a network, and the networkconfiguration network element has a function of implementing thecorresponding network management method according to the fifth aspect.The function may be implemented by hardware, or implemented by hardwareexecuting corresponding software. The hardware or software includes oneor more modules corresponding to the function. The module may besoftware and/or hardware. The network configuration network element maybe a backhaul network management network element.

According to an eleventh aspect, this application provides a QoSparameter processing method, and the method includes obtaining, by acontrol plane network element, a first QoS parameter between a firstaccess network device and a first UPF network element, and determining,by the control plane network element, a third QoS parameter between aterminal device and the first access network device based on the firstQoS parameter and a second QoS parameter that is between the terminaldevice and the first UPF network element, and sending the third QoSparameter to the first access network device, or sending, by the controlplane network element, the first QoS parameter to the first accessnetwork device, where the first QoS parameter is used to determine a QoSparameter between the terminal device and the first access networkdevice.

Therefore, compared with that, in the other approaches, the first accessnetwork device performs air interface resource scheduling based on anend-to-end QoS parameter between user equipment (UE) and a UPF, in themethod according to this embodiment of this application, the firstaccess network device may perform air interface resource schedulingbased on a more precise QoS parameter, namely, a QoS parameter betweenthe UE and an AN, optimizing usage of an air interface resource.

In a possible design, the obtaining, by a control plane network element,a first QoS parameter between a first access network device and a firstUPF network element includes obtaining, by the control plane networkelement, the first QoS parameter from the first UPF network element,obtaining, by the control plane network element, the first QoS parameterfrom a network element discovery function device, obtaining, by thecontrol plane network element, the first QoS parameter from a networkmanagement system, or obtaining, by the control plane network element,the first QoS parameter from a network data analytics function device.

In a possible design, the obtaining, by the control plane networkelement, the first QoS parameter from the first UPF network elementincludes sending, by the control plane network element, identifierinformation of the first access network device to the first UPF networkelement, and receiving, from the first UPF network element, the firstQoS parameter between the first access network device and the first UPFnetwork element. Further, in a possible design, the step furtherincludes sending, by the control plane network element, flow informationthat identifies a first flow to the first UPF network element, where thefirst QoS parameter indicates a QoS parameter that is between the firstaccess network device and the first UPF network element and thatcorresponds to the first flow.

In a possible design, the obtaining, by the control plane networkelement, the first QoS parameter from a network element discoveryfunction device includes sending, by the control plane network element,identifier information of the first access network device and identifierinformation of the first UPF network element to the network elementdiscovery function device, and receiving, from the network elementdiscovery function device, the first QoS parameter between the firstaccess network device and the first UPF network element.

In another possible design, the obtaining, by the control plane networkelement, the first QoS parameter from a network element discoveryfunction device includes sending, by the control plane network element,identifier information of the first access network device and servicearea information of the control plane network element to the networkelement discovery function device, receiving, from the network elementdiscovery function device, identifier information of at least one UPFnetwork element located in an area indicated by the service areainformation, and a QoS parameter between each of the at least one UPFnetwork element and the first access network device, and determining, bythe control plane network element, the first QoS parameter in the QoSparameter, or sending, by the control plane network element, servicearea information of the control plane network element to the networkelement discovery function device, receiving, from the network elementdiscovery function device, identifier information of at least one UPFnetwork element located in an area indicated by the service areainformation, identifier information of an access network device thatcommunicates with each of the at least one UPF network element, and aQoS parameter between each of the at least one UPF network element andthe access network device, and determining, by the control plane networkelement, the first QoS parameter in the QoS parameter based onidentifier information of the first access network device.

With reference to the foregoing possible designs, the method may furtherinclude determining, by the control plane network element, the first UPFnetwork element based on the QoS parameter that is between each of theat least one UPF network element and the access network device and thatis received from the network element discovery function device.

According to a twelfth aspect, this application provides a QoS parameterprocessing method, and the method includes obtaining, by a control planenetwork element, a first QoS parameter between a first access networkdevice and a first UPF network element, and determining, by the controlplane network element, a third QoS parameter between a terminal deviceand the first access network device based on the first QoS parameter anda second QoS parameter that is between the terminal device and the firstUPF network element, and sending the third QoS parameter to a secondaccess network device, or sending, by the control plane network element,the first QoS parameter to a second access network device, where thefirst QoS parameter is used to determine a QoS parameter between theterminal device and the first access network device, where the firstaccess network device is a target access network device that serves theterminal device after handover, and the second access network device isa source access network device that serves the terminal device beforehandover.

Therefore, compared with that in the other approaches, the first accessnetwork device performs air interface resource scheduling based on anend-to-end QoS parameter between UE and a UPF, in the method accordingto this embodiment of this application, in a handover scenario, thesecond access network device can receive the first QoS parameter or thethird QoS parameter from the control plane network element, and thensend the first QoS parameter or the third QoS parameter to the firstaccess network device such that the first access network device mayperform air interface resource scheduling based on the more precise QoSparameter, namely, the QoS parameter between the UE and an AN,optimizing the usage of the air interface resource.

In a possible design, the obtaining, by a control plane network element,a first QoS parameter between a first access network device and a firstUPF network element includes obtaining, by the control plane networkelement, the first QoS parameter from the first UPF network element,obtaining, by the control plane network element, the first QoS parameterfrom a network element discovery function device, obtaining, by thecontrol plane network element, the first QoS parameter from a networkmanagement system, or obtaining, by the control plane network element,the first QoS parameter from a network data analytics function device.

In a possible design, the obtaining, by the control plane networkelement, the first QoS parameter from the first UPF network elementincludes sending, by the control plane network element, identifierinformation of the first access network device to the first UPF networkelement, and receiving, from the first UPF network element, the firstQoS parameter between the first access network device and the first UPFnetwork element. Further, in a possible design, the step furtherincludes sending, by the control plane network element, flow informationthat identifies a first flow to the first UPF network element, where thefirst QoS parameter indicates a QoS parameter that is between the firstaccess network device and the first UPF network element and thatcorresponds to the first flow.

In a possible design, the obtaining, by the control plane networkelement, the first QoS parameter from a network element discoveryfunction device includes sending, by the control plane network element,identifier information of the first access network device and identifierinformation of the first UPF network element to the network elementdiscovery function device, and receiving, from the network elementdiscovery function device, the first QoS parameter between the firstaccess network device and the first UPF network element.

In another possible design, the obtaining, by the control plane networkelement, the first QoS parameter from a network element discoveryfunction device includes sending, by the control plane network element,identifier information of the first access network device and servicearea information of the control plane network element to the networkelement discovery function device, receiving, from the network elementdiscovery function device, identifier information of at least one UPFnetwork element located in an area indicated by the service areainformation, and a QoS parameter between each of the at least one UPFnetwork element and the first access network device, and determining, bythe control plane network element, the first QoS parameter in the QoSparameter, or sending, by the control plane network element, servicearea information of the control plane network element to the networkelement discovery function device, receiving, from the network elementdiscovery function device, identifier information of at least one UPFnetwork element located in an area indicated by the service areainformation, identifier information of an access network device thatcommunicates with each of the at least one UPF network element, and aQoS parameter between each of the at least one UPF network element andthe access network device, and determining, by the control plane networkelement, the first QoS parameter in the QoS parameter based onidentifier information of the first access network device.

With reference to the foregoing possible designs, the method may furtherinclude determining, by the control plane network element, the first UPFnetwork element based on the QoS parameter that is between each of theat least one UPF network element and the access network device and thatis received from the network element discovery function device.

According to a thirteenth aspect, this application provides a QoSparameter processing method, and the method includes obtaining, by afirst access network device, a QoS parameter between a terminal deviceand the first access network device, and scheduling, by the first accessnetwork device, an air interface resource between the terminal deviceand the first access network device based on the QoS parameter.

Therefore, compared with that, in the other approaches, the first accessnetwork device performs air interface resource scheduling based on anend-to-end QoS parameter between UE and a UPF, in the method accordingto this embodiment of this application, the first access network devicemay perform air interface resource scheduling based on a more preciseQoS parameter, namely, a QoS parameter between the UE and an AN,optimizing usage of an air interface resource.

In a possible design, the obtaining, by a first access network device, aQoS parameter between a terminal device and the first access networkdevice includes receiving, by the first access network device, from acontrol plane network element, a first QoS parameter between the firstaccess network device and a first UPF network element, and determiningthe QoS parameter between the terminal device and the first accessnetwork device based on the first QoS parameter and a second QoSparameter that is between the terminal device and the first UPF networkelement.

In another possible design, obtaining, by a first access network device,a QoS parameter between a terminal device and the first access networkdevice includes receiving, by the first access network device, the QoSparameter from a control plane network element.

In still another possible design, obtaining, by a first access networkdevice, a QoS parameter between a terminal device and the first accessnetwork device includes receiving, by the first access network device,the QoS parameter from a second access network device. In this case, themethod further includes performing, by the first access network device,handover admission control on the terminal device based on the QoSparameter, where the first access network device is a target accessnetwork device that serves the terminal device after handover, and thesecond access network device is a source access network device thatserves the terminal device before handover.

According to a fourteenth aspect, this application provides a QoSparameter processing method, and the method includes receiving, by asecond access network device, from a control plane network element, afirst QoS parameter between the first access network device and a firstUPF network element, and determining a third QoS parameter between aterminal device and the first access network device based on the firstQoS parameter and a second QoS parameter that is between the terminaldevice and the first UPF network element, or receiving, by a secondaccess network device, from a control plane network element, a third QoSparameter between a terminal device and the first access network device,and sending, by the second access network device, the third QoSparameter to the first access network device, where the first accessnetwork device is a target access network device that serves theterminal device after handover, and the second access network device isa source access network device that serves the terminal device beforehandover.

Therefore, compared with that in the other approaches, the first accessnetwork device performs air interface resource scheduling based on anend-to-end QoS parameter between UE and a UPF, in the method accordingto this embodiment of this application, in a handover scenario, thesecond access network device can receive the first QoS parameter or thethird QoS parameter from the control plane network element, and thensend the first QoS parameter or the third QoS parameter to the firstaccess network device such that the first access network device mayperform air interface resource scheduling based on the more precise QoSparameter, namely, the QoS parameter between the UE and an AN,optimizing the usage of the air interface resource.

According to a fifteenth aspect, this application provides a controlplane network element for processing a QoS parameter, and the controlplane network element has a function of implementing the correspondingQoS parameter processing method according to the eleventh or the twelfthaspect. The function may be implemented by hardware, or implemented byhardware executing corresponding software. The hardware or softwareincludes one or more modules corresponding to the function. The modulemay be software and/or hardware.

According to a sixteenth aspect, this application provides an accessnetwork device, and the access network device has a function ofimplementing the first access network device in the corresponding QoSparameter processing method according to the thirteenth aspect. Thefunction may be implemented by hardware, or implemented by hardwareexecuting corresponding software. The hardware or software includes oneor more modules corresponding to the function. The module may besoftware and/or hardware.

According to a seventeenth aspect, this application provides an accessnetwork device, and the access network device has a function ofimplementing the second access network device in the corresponding QoSparameter processing method according to the fourteenth aspect. Thefunction may be implemented by hardware, or implemented by hardwareexecuting corresponding software. The hardware or software includes oneor more modules corresponding to the function. The module may besoftware and/or hardware.

According to an eighteenth aspect, this application provides a computerstorage medium, including an instruction. When the instruction is run ona computer, the computer is enabled to perform the method according toany one of the first to the fifth aspects or any one of the eleventh tothe fourteenth aspects.

According to a nineteenth aspect, this application provides a computerapparatus, including at least one connected processor, a memory, and atransceiver. The memory is configured to store program code, and theprocessor is configured to invoke the program code in the memory toperform the method according to any one of the first to the fifthaspects or any one of the eleventh to the fourteenth aspects.

According to a twentieth aspect, this application provides acommunications system, and the communications system may include aterminal device, the control plane network element according to thesixth aspect, and the communications apparatus according to the seventhaspect.

Based on the twentieth aspect, in a first implementation of thetwentieth aspect, the communications system may further include thenetwork management network element according to the ninth aspect, thenetwork configuration network element according to the tenth aspect, anda data management network element. The data management network elementis configured to store the capability information, of the backhaulnetwork, from the network configuration network element according to thetenth aspect.

Based on the twentieth aspect or the first implementation of thetwentieth aspect, in a second implementation of the twentieth aspect,the communications system may further include the session managementfunction network element according to the ninth aspect.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1A is a schematic diagram of a feature of a best effort servicedata packet;

FIG. 1B is a schematic diagram of a feature of a deterministic servicedata packet;

FIG. 1C is a schematic structural diagram of a communications systemaccording to an embodiment of this application;

FIG. 2 is a schematic flowchart for configuring a backhaul networkaccording to an embodiment of this application;

FIG. 3A is a schematic flowchart of a QoS parameter processing methodaccording to an embodiment of this application;

FIG. 3B is another schematic flowchart of a QoS parameter processingmethod according to an embodiment of this application;

FIG. 4 is a schematic processing flowchart for forwarding an uplink datapacket based on a QoS parameter by a forwarding plane network elementaccording to an embodiment of this application;

FIG. 5 is a schematic processing flowchart for forwarding a downlinkdata packet based on a QoS parameter by a forwarding plane networkelement according to an embodiment of this application;

FIG. 6 is another schematic flowchart of a QoS parameter processingmethod according to an embodiment of this application;

FIG. 7 is a schematic flowchart for re-dividing a first QoS parameter ina handover scenario according to an embodiment of this application;

FIG. 8 is a schematic flowchart for re-dividing a first QoS parameter ina handover scenario according to an embodiment of this application;

FIG. 9 is a schematic structural diagram of a control plane networkelement according to an embodiment of this application;

FIG. 10 is a schematic structural diagram of a communications apparatusaccording to an embodiment of this application;

FIG. 11 is a schematic structural diagram of a session managementfunction network element according to an embodiment of this application;

FIG. 12 is a schematic structural diagram of a network managementnetwork element according to an embodiment of this application;

FIG. 13 is a schematic structural diagram of a network configurationnetwork element according to an embodiment of this application;

FIG. 14 is a schematic structural diagram of a communications systemaccording to an embodiment of this application;

FIG. 15 is a schematic structural diagram of a physical device thatperforms a QoS parameter processing method or a network managementmethod according to an embodiment of this application;

FIG. 16A is a schematic flowchart of a QoS parameter processing methodaccording to an embodiment of this application;

FIG. 16B is a schematic flowchart of another QoS parameter processingmethod according to an embodiment of this application;

FIG. 17 is a signaling interaction diagram of processing a QoS parameteraccording to an embodiment of this application;

FIG. 18A and FIG. 18B are another signaling interaction diagram ofprocessing a QoS parameter according to an embodiment of thisapplication;

FIG. 19 is still another signaling interaction diagram of processing aQoS parameter according to an embodiment of this application;

FIG. 20 is a signaling interaction diagram of a QoS parameter processingmethod performed in a handover preparation phase based on Xn handoveraccording to an embodiment of this application;

FIG. 21 is a signaling interaction diagram of a QoS parameter processingmethod performed in a handover preparation phase based on N2 handoveraccording to an embodiment of this application;

FIG. 22 is a signaling interaction diagram of a QoS parameter processingmethod performed in a handover complete phase based on Xn handoveraccording to an embodiment of this application; and

FIG. 23 is a schematic flowchart of a QoS parameter processing method ina handover phase according to an embodiment of this application.

DESCRIPTION OF EMBODIMENTS

In the specification, claims, and accompanying drawings of thisapplication, the terms “first”, “second”, and so on are intended todistinguish between similar objects but do not necessarily indicate aspecific order or sequence. It should be understood that the data termedin such a way are interchangeable in proper circumstances so that theembodiments of the present disclosure described herein can beimplemented in other orders than the order illustrated or describedherein. Moreover, the terms “include”, “contain” and any other variantsmean to cover the non-exclusive inclusion, for example, a process,method, system, product, or device that includes a list of steps ormodules is not necessarily limited to those modules, but may includeother modules not expressly listed or inherent to such a process,method, system, product, or device.

In a 5th generation (5G) communications network, an application scenarioof Ultra-Reliable Low-Latency Communications (URLLC) is proposed. FIG.1A is a schematic diagram of a feature of a conventional best effortservice data packet. Compared with the conventional best effort service,in the application scenario of the URLLC, an end-to-end latency andjitter of a service may be required to have strict boundaries. A servicesatisfying this requirement is referred to as a deterministic service.FIG. 1B is a schematic diagram of a feature of a deterministic servicedata packet. FIG. 1B shows that three features, namely, bufferallocation, an end-to-end latency, and an end-to-end latency variationvalue, of the deterministic service data packet each have a boundedboundary.

For example, a deterministic service may be applied to a field such asan industrial control network, the internet of vehicles, telemedicine,or a smart grid. The industrial control network is a computer networkthat has a real-time digital communication capability, may be a networkor a heterogeneous network in which a plurality of field buses areintegrated, and can implement information exchange betweeninterconnected devices or systems. For example, for a service on theindustrial control network, an end-to-end latency needs to not exceed 1millisecond (ms), an end-to-end jitter needs to not exceed 1microseconds (μs), and end-to-end reliability needs to be at least99.9999%. For the service of the industrial control network, even ifonly several packets are not delivered as required, a serious problemmay occur.

It can be learned that the deterministic service requires a 5Gcommunications network to be capable of satisfying, in any case, arequirement for a bounded end-to-end latency and jitter and highreliability. A network that can satisfy such a requirement may bereferred to as a Deterministic Networking (DetNet). The DetNet hasconstraint features such as a latency, a jitter, bandwidth, andreliability that are controlled. The DetNet is a Time-SensitiveNetworking (TSN).

This application provides a QoS parameter processing solution, and thesolution may be used to process a QoS parameter of the foregoingdeterministic service. The solution may be used for a communicationssystem shown in FIG. 1C.

For example, the communications system includes an access network device1, a UPF network element 2, and a deterministic coordinator (DC) 3, adata management network element 4, a backhaul network configurationnetwork element 5, a network management network element 6, a sessionmanagement function (SMF) network element 7, and an application server8.

The access network device 1 may be a communications apparatus in a RAN,and is a communications infrastructure that provides a wirelesscommunications service. The access network device is configured toconnect the terminal device to a core network using the RAN, andschedule the terminal device. For example, the access network device 1(for example, a base station) provides a signal for the terminal device,and is responsible for sending downlink data to the terminal device orsending uplink data of the terminal device to the UPF network element.The access network device 1 may include base stations in various forms,for example, a macro base station, a micro base station (also referredto as a small cell), a relay node, and an access point. In systems usingdifferent radio access technologies, names of devices having a basestation function may be different. For example, in a 3rd generationsystem, the device is referred to as a NodeB. In a Long-Term Evolution(LTE) system, the system is referred to as an evolved NodeB (eNB oreNodeB). In a 5G system, the device is referred to as a gNB (gNodeB).

The UPF network element 2 is responsible for sending downlink data tothe access network device or sending uplink data of the access networkdevice to the application server.

The data management network element 4 is configured to storesubscription data of the terminal device. For example, the datamanagement network element may include a unified data management (UDM)network element.

The backhaul network configuration network element 5 is configured toconfigure a backhaul network between the RAN and the UPF networkelement. The backhaul network is a transmission network between theaccess network device and the UPF network element. The backhaul networkmay also be referred to as a transmission network. The backhaul networkmay include a switching network constituted by forwarding devices suchas a switch and a router. For example, the backhaul networkconfiguration network element may be a centralized network configuration(CNC) unit.

The network management network element 6 is configured to manage amobile network and the backhaul network. For example, the networkmanagement network element may be configured to manage the forwardingdevices, such as the switch and the router, in the backhaul network. Thenetwork management network element can interact with the backhaulnetwork configuration network element.

The session management function network element 7 may be responsible forestablishing, deleting, or modifying a session.

The application server 8 is responsible for sending downlink data to theUPF network element or receiving uplink data sent by the UPF networkelement.

In the foregoing communications system, a data packet is forwardedthrough a plurality of network domains. For example, the network domainsthat the data packet passes through may include the RAN, the backhaulnetwork, and the UPF network element 2. In a process in which the datapacket is forwarded through the plurality of network domains, acommunications apparatus of each network domain forwards the datapacket. For example, in the network domain of the RAN, thecommunications apparatus is an access network device (for example, theaccess network device 1) in the RAN. In the network domain of thebackhaul network, the communications apparatus is a forwarding device inthe backhaul network. In the network domain of the UPF network element2, the communications apparatus is the UPF network element.

In this embodiment of this application, a deterministic coordinator 3 isintroduced into the communications system shown in FIG. 1C. Thedeterministic coordinator 3 may be an independently deployed networkelement, or may be a logical network element integrated in the sessionmanagement function network element 7 (where, it may alternatively beconsidered that a deterministic coordination function is integrated inthe session management function network element 7). When thedeterministic coordinator 3 is integrated in the session managementfunction network element 7, the session management function networkelement 7 can implement all functions that are the same as or similar tothose of the deterministic coordinator 3. The deterministic coordinator3 may be responsible for assigning QoS parameters to the three networkdomains: the RAN, the UPF network element, and the backhaul network. Inthe following description, the deterministic coordinator 3 configured toassign the QoS parameters to the network domains or the sessionmanagement function network element 7 in which the deterministiccoordination function is integrated is referred to as a control planenetwork element.

Based on the communications system shown in FIG. 1C, this applicationprovides the following technical solution.

In a session establishment phase or a handover phase, the control planenetwork element may divide a QoS parameter (that is, an end-to-end QoSparameter) between the terminal device and the UPF network element basedon capability information of the backhaul network, capabilityinformation of the RAN, and capability information of the UPF networkelement, to obtain a QoS parameter of each network domain, sends firstinformation related to the QoS parameter of each network domain to eachnetwork domain. For example, for the two network domains the RAN and theUPF network element, the control plane network element may deliver acorrespondence between each QoS parameter obtained after division and aflow identifier such that the access network device and the UPF networkelement can complete data packet forwarding based on the QoS parametercorresponding to the flow identifier. For the network domain of thebackhaul network, the control plane network element may deliver acorrespondence between a flow identifier and a stream identifier suchthat the forwarding device in the backhaul network completes data packetforwarding based on the correspondence between a flow identifier and astream identifier. In this way, resource scheduling can be preciselyperformed on each network domain, ensuring that transmission of thedeterministic service satisfies a requirement.

Before a procedure of a QoS parameter processing method is described,the following first describes a method for configuring a backhaulnetwork. Capability information of a network domain of the backhaulnetwork may be obtained using the method in FIG. 2. As shown in FIG. 2,this method may include the following steps.

201. A network management network element sends a configuration requestto a backhaul network configuration network element.

For example, the network management network element may be the networkmanagement network element 6 in FIG. 1C. The backhaul networkconfiguration network element may be the backhaul network configurationnetwork element 5 in FIG. 1C.

The configuration request is used to request to configure capabilityinformation of the backhaul network. For example, the configurationrequest may include an expected value of a QoS parameter of the backhaulnetwork, an IP address of an access network device, and an IP address ofa UPF network element. The expected value of the QoS parameter of thebackhaul network may include at least one of an expected value of alatency parameter, an expected value of a jitter parameter, and anexpected value of reliability of the backhaul network. The IP address ofthe access network device and the IP address of the UPF network elementmay be used to identify the backhaul network.

202. Based on the configuration request, the backhaul networkconfiguration network element creates a backhaul network and configurescapability information of the backhaul network.

For example, the backhaul network configuration network elementconfigures the capability information of the backhaul network based onan idle network resource in the backhaul network and the expected valueof the QoS parameter of the backhaul network. In a possibleimplementation, if the backhaul network configuration network elementcan configure, based on a current idle network resource, the backhaulnetwork that satisfies the expected value of the QoS parameter, thebackhaul network configuration network element may configure thecapability information of the backhaul network based on the expectedvalue of the QoS parameter in the configuration request. In anotherpossible implementation, if a current idle network resource cannotsatisfy the expected value of the QoS parameter, the backhaul networkconfiguration network element may configure the capability informationof the backhaul network in a manner in which the expected value of theQoS parameter is satisfied as much as possible.

The capability information of the backhaul network includes a streamidentifier of a service flow in the backhaul network, a quantity ofavailable service flows, and a QoS parameter of the service flow. Forexample, the QoS parameter of the service flow may include a latencyparameter and a jitter parameter of the service flow. Further, the QoSparameter of the service flow may further include a bandwidth parameterand reliability. For example, for the capability information of thebackhaul network, refer to content in the following Table 1.

TABLE 1 Stream Latency Jitter Quantity of available identifier parameterparameter service flows Stream 1 001 1 ms 10 μs 50 Stream 2 002 5 ms 100μs 100 Stream 3 003 10 ms  1 ms 200

In Table 1, the stream 1, the stream 2, and the stream 3 are streams,for transmitting service data, in the backhaul network, and the streamidentifiers are used to identify the streams for transmitting theservice data. The latency parameter is a maximum value of the latencyparameter when service data is transmitted on a stream, and the jitterparameter is a maximum value of the jitter parameter when the servicedata is transmitted on the stream. Each stream may carry a plurality ofservice flows used to transmit service data. The quantity of availableservice flows indicates a quantity of service flows that remain in astream and are available for transmitting service data. When one serviceflow of a stream is used to transmit service data, a quantity ofavailable service flows of the stream is decreased by 1, and thecapability information of the backhaul network shown in Table 1 issynchronously updated. When the quantity of available service flows is0, it indicates that the stream has no service flow available fortransmitting service data.

In the example in Table 1, the backhaul network includes three streams:the stream 1, the stream 2, and the stream 3. The stream 1 correspondsto the stream identifier 001, the latency parameter is 1 ms, the jitterparameter is 10 μs, and there are 50 available service flows. The stream2 corresponds to the stream identifier 002, the latency parameter is 5ms, the jitter parameter is 100 μs, and there are 100 available serviceflows. The stream 3 corresponds to the stream identifier 003, thelatency parameter is 10 ms, the jitter parameter is 1 ms, and there are200 available service flows.

203. The backhaul network configuration network element sends thecapability information of the backhaul network to the network managementnetwork element.

204. The network management network element receives, from the backhaulnetwork configuration network element, the capability information of thebackhaul network, and sends the capability information of the backhaulnetwork to a data management network element.

For example, the data management network element may be the datamanagement network element 4 in FIG. 1C. After receiving the capabilityinformation of the backhaul network, the data management network elementmay store the capability information of the backhaul network in the datamanagement network element.

In another possible implementation, step 204 may be replaced with step205. The network management network element receives, from the backhaulnetwork configuration network element, the capability information of thebackhaul network, and sends the capability information of the backhaulnetwork to a deterministic coordinator. For example, the deterministiccoordinator may be the deterministic coordinator 3 in FIG. 1C.Correspondingly, after receiving the capability information of thebackhaul network, the deterministic coordinator may store the capabilityinformation of the backhaul network in the deterministic coordinator.

It can be learned that, when the backhaul network configuration networkelement cannot interact with a control plane (for example, the datamanagement network element or the deterministic coordinator) of the 3GPPbecause there is no interface therebetween, the network managementnetwork element in this embodiment of this application may serve as arelay between the backhaul network and the control plane of the 3GPP, tobe specific, the backhaul network configuration network element sends,through forwarding by the network management network element, thecapability information of the backhaul network to be transmitted to thedata management network element or the deterministic coordinator, andsubsequently the control plane network element (that may alternativelybe the deterministic coordinator) may determine a QoS parameter of eachnetwork domain based on the capability information of the backhaulnetwork.

This application further provides a QoS parameter processing method thatis performed after the backhaul network is configured. Refer to FIG. 3A.The method includes the following steps.

301. A control plane network element obtains a first QoS parameterbetween a terminal device and a UPF network element and capabilityinformation of a first network domain.

The first QoS parameter is a QoS parameter between the terminal deviceand the UPF network element. For example, the first QoS parameterincludes at least one of a latency parameter, a jitter parameter, and areliability parameter. The first QoS parameter defines the QoS parameterbetween the terminal device and the UPF network element. It should benoted that the first QoS parameter does not limit a specific UPF networkelement that establishes a session with the terminal device, and thefirst QoS parameter does not change due to a change of the UPF networkelement that establishes a session connection to the terminal device.

For example, the control plane network element may obtain subscriptiondata of the terminal device. For example, the subscription data of theterminal device is data corresponding to a service subscribed to by theterminal device. That is, the subscription data of the terminal devicemay include a QoS parameter, account information, a service type, aservice class, a transmit frequency and a size of a data packet, and thelike that correspond to the service subscribed to by the terminaldevice. The control plane network element may obtain the first QoSparameter from the subscription data.

The first network domain includes at least one of a RAN, a backhaulnetwork, and the UPF network element. The following separatelydescribes, based on a type of the first network domain, animplementation of obtaining, by the control plane network element, thecapability information of the first network domain.

1. When the first network domain includes the RAN or the UPF networkelement, the implementation of obtaining, by the control plane networkelement, the capability information of the first network domain includeseither of the following two:

(a) The control plane network element sends a request message to thefirst network domain, after receiving the request message from thecontrol plane network element, a communications apparatus in the firstnetwork domain feeds back the capability information of the firstnetwork domain to the control plane network element. For example, therequest message includes the transmit frequency and the size of the datapacket, and the capability information of the first network domain isassociated with the transmit frequency and the size of the data packet.For example, the control plane network element may obtain the transmitfrequency and the size of the data packet from the subscription data ofthe terminal device. After receiving the transmit frequency and the sizeof the data packet from the control plane network element, thecommunications apparatus in the first network domain may determine thecapability information of the first network domain based on the transmitfrequency and the size of the data packet, and feed back the determinedcapability information of the first network domain to the control planenetwork element.

For example, the communications apparatus may determine, based on thetransmit frequency and the size of the data packet, a channel that needsto serve a service flow, determine a transmit time-slot (a time requiredfor sending one data packet) based on the size of the data packet, anddetermine a time interval of the transmit time-slot based on thetransmit frequency of the data packet, and determine, based on the timeinterval of the transmit time-slot, the earliest and latest sending timepoints after the data packet arrives at the communications apparatus. Inthis way, a latency parameter and a jitter parameter in the capabilityinformation are determined. In addition, the communications apparatusmay further determine a reliability parameter based on quality of achannel.

For example, if the transmit frequency of the data packet is 10/ms (thatis, 10 data packets are sent every 1 ms), and the size of the datapacket is 40 bytes, a value of the transmit time-slot is 1 ms (that is,1 ms needs to be spent on sending one data packet). Because aretransmission latency needs to be considered, a maximum latency is1+1+1=3 ms. Therefore, a value range of the latency parameter is 1 ms to3 ms. A minimum time interval of a transmit time-slot of thecommunications apparatus is 0.025 ms. Because a transmit frequency of aservice flow is 10/ms, a maximum time interval of a transmit time-slotreserved for the service flow is 0.1 ms. Therefore, a value range of thejitter parameter is 25 μs to 100 μs. A reliability parameter of thechannel is 99.9% to 99.9999%.

(b) The communications apparatus of the first network domain mayperiodically report the capability information of the first networkdomain to the control plane network element, and the control planenetwork element may receive, from the first network domain, thecapability information periodically reported by the first networkdomain.

In addition, when the first network domain includes the RAN, in additionto the foregoing periodic reporting manner, an access network device inthe RAN may further report the capability information of the firstnetwork domain to the control plane network element after receiving ahandover request from another access network device.

For the manner (a) and the manner (b), a communications apparatus in anetwork domain of the RAN may refer to the access network device. Acommunications apparatus in a network domain of the UPF network elementmay refer to the UPF network element.

It can be learned that in the foregoing manner (a) or (b), the controlplane network element may obtain capability information of the networkdomain of the RAN (capability information of the RAN) or capabilityinformation of the network domain of the UPF network element (capabilityinformation of the UPF network element). In addition, because a possiblechange of a service flow accessed by the RAN is considered in the manner(a) or (b), the control plane network element can more precisely andproperly assign a corresponding QoS parameter to each network domainbased on the capability information, of the network domain, obtained inthe foregoing manner, further ensuring transmission of a deterministicservice.

For example, Table 2 and Table 3 are respectively a representation formof the capability information reported by the UPF network element and arepresentation form of the capability information reported by the accessnetwork device.

TABLE 2 Latency Jitter Reliability 0.5 ms to 5 ms 10 μs to 50 μs 99.9%to 99.9999%

TABLE 3 Latency Jitter Reliability 1 ms to 5 ms 10 μs to 50 μs 99.9% to99.9999%

Table 2 indicates that the latency that can be implemented by thenetwork domain of the UPF network element is 0.5 ms to 5 ms, the jitteris 10 μs to 50 μs, and the reliability is 99.9999% to 99.9%.

Table 3 indicates that the latency that can be implemented by thenetwork domain of the access network device is 1 ms to 5 ms, the jitteris 10 μs to 50 μs, and the reliability is 99.9999% to 99.9%.

A manner and an occasion of obtaining the capability information of thefirst network domain are not limited in this application.

2. When the first network domain includes the backhaul network, thecontrol plane network element may obtain capability information of thebackhaul network in either of the following two manners.

The control plane network element may receive, from the networkmanagement network element, the capability information of the backhaulnetwork, in a configuration phase of the backhaul network (for example,using step 205 in FIG. 2).

The data management network element may receive, from the networkmanagement network element, the capability information of the backhaulnetwork, in the configuration phase of the backhaul network (forexample, using step 204 in FIG. 2). Subsequently, the control planenetwork element may obtain, from the data management network element,the capability information of the backhaul network.

For the capability information of the backhaul network, refer to thedescription of step 202 in FIG. 2. Details are not described hereinagain.

302. The control plane network element determines a second QoS parameterof the first network domain based on the capability information of thefirst network domain and the first QoS parameter.

For example, the second QoS parameter includes at least one of a latencyparameter, a jitter parameter, and a reliability parameter.

By performing step 302, the control plane network element may divide thefirst QoS parameter between the terminal device and the UPF networkelement. For example, the control plane network element may divide thefirst QoS parameter into three QoS parameters respectively for thenetwork domain of the RAN, a network domain of the backhaul network, andthe network domain of the UPF network element. The three QoS parametersrespectively correspond to the network domain of the RAN, the networkdomain of the backhaul network, and the network domain of the UPFnetwork element. That is, a QoS parameter obtained after divisioncorresponds to the network domain. Alternatively, the control planenetwork element may divide the first QoS parameter into two QoSparameters. For example, after the first QoS parameter is divided, anytwo of the foregoing three network domains correspond to one QoSparameter, and the remaining network domain corresponds to the other QoSparameter.

That is, the first network domain may be the RAN, the backhaul network,or the UPF network element, or may be any two of the RAN, the backhaulnetwork, or the UPF network element.

In addition, a type of the second QoS parameter corresponds to aparameter type in the first QoS parameter. For example, when the firstQoS parameter includes the latency parameter, a QoS parameter obtainedafter division also includes the latency parameter. When the first QoSparameter includes the latency parameter, the jitter parameter, and thereliability parameter, the QoS parameter obtained after division alsoincludes the latency parameter, the jitter parameter, and thereliability parameter.

After division, a sum of latency parameters of the network domains doesnot exceed an end-to-end latency parameter in the first QoS parameter. Asum of jitter parameters of the network domains does not exceed anend-to-end jitter parameter in the first QoS parameter. A product ofreliability parameters of the network domains does not exceed anend-to-end reliability parameter in the first QoS parameter.

For example, before division, the first QoS parameter includes alatency, a jitter, and reliability, as shown in Table 4. A flowidentifier of a QoS flow corresponding to the QoS parameter is 005. Forexample, the flow identifier may be a QoS flow identifier (QFI). Thecontrol plane network element may divide the first QoS parameter basedon the first QoS parameter and the capability information of the networkdomains shown in Table 1, Table 2, and Table 3. QoS parameters obtainedafter division each include a latency, a jitter, and reliability. Afterdivision, the QoS parameters of the RAN, the backhaul network, and theUPF network element are shown in Table 5.

TABLE 4 Latency Jitter Reliability 10 ms 100 μs 99.999%

TABLE 5 Latency Jitter Reliability RAN 5 ms 50 μs 99.9999% Backhaulnetwork 3 ms 10 μs 99.999% UPF network element 2 ms 40 μs 99.9999%

In Table 4, the end-to-end first QoS parameter includes the 10 mslatency, the 100 μs jitter, and the 99.999% reliability. After division,as shown in Table 5, the QoS parameter of the RAN includes the 5 mslatency, the 50 μs jitter, and the 99.9999% reliability, the QoSparameter of the backhaul network includes the 3 ms latency, the 10 μsjitter, and the 99.999% reliability, and the QoS parameter of the UPFnetwork element includes the 2 ms latency, the 40 μs jitter, and the99.9999% reliability. After division, the QoS parameter of the backhaulnetwork corresponds to the QoS parameter of the stream 1 whose streamidentifier is 001 in the backhaul network in Table 1. That is, a resultof the division shows that, the QoS parameter of the backhaul networkcan be satisfied by transmitting a data packet using the stream 1 whosestream identifier is 001 in the backhaul network.

Based on a comparison between Table 4 and Table 5, it can be learnedthat, in the other approaches, originally the UPF network element canperform data packet forwarding and resource scheduling only based on theQoS parameter in Table 4. After the QoS parameter in Table 4 is dividedusing a solution in this application, the UPF network element canperform data packet forwarding and resource scheduling based on the 2 mslatency, the 40 μs jitter, and the 99.9999% reliability. It is similarfor the two network domains: the RAN and the backhaul network. It can belearned that, compared with the end-to-end QoS parameter in Table 4, theQoS parameter, of each network domain, obtained after division and shownin Table 5 in this application enables the communications apparatus inthe first network domain to more precisely complete data packetforwarding and resource scheduling.

In some implementations, when determining the second QoS parameter, thecontrol plane network element may determine the second QoS parameter forthe first network domain based on the capability information of thefirst network domain, the first QoS parameter, and a priority of thefirst network domain.

For example, when dividing the QoS parameter, the control plane networkelement may preferentially assign a QoS parameter to the RAN, and mayallocate, to the RAN based on the capability information of the RAN,fewest (or as-few-as-possible) resources required to satisfy a QoSparameter of the deterministic service. For example, a latency that canbe provided by the RAN is 1 to 6 ms. On the premise that a requirementof the QoS parameter of the deterministic service is satisfied, thecontrol plane network element may assign a 5 ms latency to the RAN. Whenthe latency is 5 ms, not only the requirement of the QoS parameter ofthe deterministic service can be satisfied, but also relatively fewresources in the RAN are occupied. If a 2 ms latency is assigned (where,a requirement on the latency is higher), relatively many resources inthe RAN are occupied. It can be learned that, according to this divisionprinciple, a QoS parameter of the first network domain can be moreproperly assigned, and subsequent QoS parameter re-division caused byreasons such as improper allocation of a resource and terminal devicehandover is reduced, reducing an unnecessary procedure of the controlplane network element.

In some implementations, before determining the second QoS parameter,the control plane network element may further determine whether thefirst QoS parameter satisfies a division condition.

For example, when the control plane network element is a sessionmanagement function network element in which a deterministiccoordination function is integrated, the control plane network elementmay determine, based on subscription data of the terminal device,whether to divide the first QoS parameter. For example, when thesubscription data includes second information used to indicate that aservice of the terminal device includes a deterministic service, thecontrol plane network element may determine that the service of theterminal device includes the deterministic service, and the controlplane network element needs to divide the first QoS parameter. In thisway, the control plane network element may determine a second QoSparameter of the first network domain based on the capabilityinformation of the first network domain and the first QoS parameter.

When the control plane network element is an independently deployeddeterministic coordinator, the session management function networkelement may determine, based on the subscription data of the terminaldevice, whether to divide the first QoS parameter. Similarly, when thesubscription data includes the second information used to indicate thatthe service of the terminal device includes the deterministic service,the session management function network element may determine that theservice of the terminal device includes the deterministic service, andrequest the control plane network element to divide the first QoSparameter. After receiving the request, the control plane networkelement may determine the second QoS parameter of the first networkdomain based on the capability information of the first network domainand the first QoS parameter.

Optionally, the second information may include a jitter parameter or aflow identifier of a service flow of the deterministic service. That is,if the subscription data includes the jitter parameter or the flowidentifier of the service flow of the deterministic service, the serviceof the terminal device includes the deterministic service having arelatively high requirement for transmission stability. Therefore, thecontrol plane network element needs to assign a QoS parameter to eachnetwork domain of the terminal device. In this way, it can be ensuredthat transmission of the deterministic service of the terminal devicesatisfies a requirement.

It can be learned that, whether the control plane network element needsto divide a QoS parameter corresponding to a service can be determinedusing an explicit indication in the subscription data. In this way, theQoS parameter can be divided pertinently. For a terminal device thatdoes not have a requirement for a deterministic service or has adeterministic service with a relatively low requirement, an unnecessaryQoS parameter division procedure may be reduced.

In some implementations, the control plane network element may furtherupdate capability information of the backhaul network. For example,after the service QoS parameter is divided, on the premise thatdeterministic transmission is ensured, the control plane network elementmay update a quantity of available service flows in the capabilityinformation of the backhaul network. For example, an original quantityof available service flows that can be supported by the backhaul networkcan be reduced. The capability information of the backhaul network isdynamically adjusted such that a stream resource in the backhaul networkcan be accurately controlled, optimizing the backhaul network.

303. The control plane network element sends first information of thesecond QoS parameter to the first network domain.

The following separately describes, based on the type of the firstnetwork domain, implementations of delivering the first information bythe control plane network element.

When the first network domain includes the RAN or the UPF networkelement, the first information of the second QoS parameter may include acorrespondence between a flow identifier and the second QoS parameter,and the flow identifier is used to identify a QoS flow between theterminal device and the UPF network element.

For example, when the first network domain includes the RAN, the firstinformation may include a correspondence between a flow identifier and aQoS parameter of the RAN. When the first network domain includes the UPFnetwork element, the first information may include a correspondencebetween a flow identifier and a QoS parameter of the UPF networkelement.

With reference to the example mentioned in step 302, the flow identifieris 005. Therefore, for the RAN, the first information may be that shownin Table 6. For the UPF network element, the first information may bethat shown in Table 7.

TABLE 6 Latency Jitter Reliability Flow identifier RAN 5 ms 50 μs99.9999% 005

TABLE 7 Latency Jitter Reliability Flow identifier UPF network element 2ms 40 μs 99.9999% 005

In this way, after receiving a data packet, the communications apparatusin the first network domain may determine, based on a flow identifier inthe data packet and a correspondence between the received flowidentifier and the second QoS parameter, the second QoS parameter forforwarding the data packet. How the communications apparatus in thefirst network domain forwards the data packet based on thecorrespondence between a flow identifier and a QoS parameter of the UPFnetwork element is further described with reference to FIG. 4 or FIG. 5below.

When the first network domain includes the backhaul network, the firstinformation of the second QoS parameter includes a correspondencebetween a flow identifier and a stream identifier, the flow identifieris used to identify a QoS flow between the terminal and the UPF networkelement, and the stream identifier is used to identify a stream that isin the backhaul network and that satisfies the second QoS parameter.

For example, with reference to the example mentioned in step 302, theflow identifier is the 005, and the QoS parameter of the backhaulnetwork after the division corresponds to the QoS parameter of thestream 1 whose stream identifier is 001 in the backhaul network inTable 1. Therefore, the first information is a correspondence betweenthe flow identifier 005 and the stream identifier 001.

In this way, after receiving an uplink data packet, the access networkdevice may determine, based on a flow identifier in the uplink datapacket and a correspondence between the received flow identifier and astream identifier, a stream that is in the backhaul network and that cansatisfy the second QoS parameter, and encapsulate the stream identifierinto the uplink data packet. In this way, after receiving the uplinkdata packet, the communications apparatus (a forwarding device such as aswitch or a router) in the backhaul network may transmit the uplink datapacket through the stream. Similarly, the UPF network element mayforward a downlink data packet based on the correspondence between aflow identifier and a stream identifier through a stream in the backhaulnetwork. How the communications apparatus in the backhaul networkforwards the data packet based on the correspondence between a flowidentifier and a stream identifier is further described with referenceto FIG. 4 or FIG. 5 below.

In this embodiment of this application, the control plane networkelement determines the second QoS parameter of the first network domain(that is, determines a QoS parameter of at least one network domain)based on the capability information of the first network domain and thefirst QoS parameter, to be specific, separately assigns a proper QoSparameter to each network domain, and then separately delivers the QoSparameter to each network domain, ensuring that the QoS parameterobtained by each network domain is a QoS parameter of the correspondingnetwork domain. Compared with an existing mechanism in which eachnetwork domain can be scheduled based on only an end-to-end indicator,in this embodiment of this application, a communications apparatus ineach network domain can perform precise scheduling based on the QoSparameter of the corresponding network domain, ensuring deterministictransmission and improving user experience. In addition, because the QoSparameter of each network domain may be dynamically assigned, resourceutilization can be improved.

It should be noted that, the determining, of the second QoS parameter,implemented using the method shown in FIG. 3A may refer to the firstdivision of the QoS parameter, or may be subsequent re-division of theQoS parameter.

For example, the foregoing step 302 and step 303 may be the firstdivision that occurs in a procedure in a session establishment phase, ormay be re-division that occurs in a procedure in a handover phase. Thefirst division that occurs in the procedure in the session establishmentphase is further described with reference to FIG. 6 below. There-division that occurs in the procedure in the handover phase isfurther described with reference to FIG. 7 or FIG. 8 below.

In addition, when the first network domain includes the RAN, thecapability information of the RAN may change, and the control planenetwork element may further update the QoS parameter of the firstnetwork domain based on changed capability information of the RAN.

For example, in a possible implementation, the communications apparatus(for example, a first access network device) in the RAN may periodicallysend the capability information of the RAN to the control plane networkelement. When the control plane network element determines that a dataradio bearer in the first network domain does not satisfy any one of theQoS parameter of the first network domain, and a transmit frequency anda size of a data packet, the control plane network element may re-dividethe QoS parameter of the first network domain based on changedcapability information of the RAN, and send QoS parameters obtainedafter the re-division to the first network domain.

In another possible implementation, when a first access network devicedetermines that a QoS parameter of a RAN in which the first accessnetwork device is located does not satisfy any one of the QoS parameterof the RAN in which the first access network device is located, a sizeof a data packet, and a transmit frequency, the first access networkdevice may send the capability information of the RAN in which the firstaccess network device is located to the control plane network element,and request the control plane network element to re-divide the QoSparameter of the first network domain. After receiving the request, thecontrol plane network element responds to the request for re-dividingthe QoS parameter of the first network domain, and re-divides the QoSparameter of the first network domain based on changed capabilityinformation of the RAN.

In addition, when the subscription data of the terminal device changes,if determining, based on the updated subscription data, that a conditionfor dividing the QoS parameter is still satisfied, the sessionmanagement function network element may alternatively request thedeterministic coordinator to re-divide the QoS parameter. Details ofthis procedure are not described.

FIG. 3B shows a method on a communications apparatus side of a firstnetwork domain. The method includes the following steps.

311. A communications apparatus in the first network domain sendscapability information of the first network domain to a control planenetwork element.

The capability information of the first network domain is used todetermine a QoS parameter of the first network domain, and the firstnetwork domain includes a RAN or a UPF network element.

A communications apparatus in a network domain of the RAN may refer toan access network device. A communications apparatus in a network domainof the UPF network element may refer to the UPF network element.

Before step 311, the method may further include receiving, by thecommunication device in the first network domain, a request message fromthe control plane network element. For example, the request messageincludes a transmit frequency and a size of a data packet, and thecapability information of the first network domain is associated withthe transmit frequency and the size of the data packet. After receivingthe transmit frequency and the size of the data packet from the controlplane network element, the communications apparatus in the first networkdomain may determine the capability information of the first networkdomain based on the transmit frequency and the size of the data packet.

After the communications apparatus in the first network domain sends thecapability information of the first network domain to the control planenetwork element, the control plane network element may divide anend-to-end QoS parameter between a terminal device and the UPF networkelement based on capability information of each network domain.

For the capability information of the first network domain, refer to thedescription of step 301 in FIG. 3A. Details are not described hereinagain.

312. The communications apparatus receives, from the control planenetwork element, first information of the QoS parameter of the firstnetwork domain.

For a feature of the first information, refer to the description of thefirst information in step 303 in FIG. 3A. Details are not describedherein again.

According to the method in FIG. 3B, the communications apparatus in thefirst network domain provides the capability information of the firstnetwork domain for the control plane network element such that thecontrol plane network element can accurately determine the QoS parameterof the first network domain, and the communications apparatus of thefirst network domain obtains, from the control plane network element,the QoS parameter of the first network domain. Therefore, acommunications apparatus in a network domain can perform precisescheduling based on a QoS parameter of this network domain, ensuring thedeterministic transmission and improving user experience and resourceutilization of a mobile network.

FIG. 4 shows how a communications apparatus in each network domainimplements downlink data packet forwarding after receiving a QoSparameter after division. FIG. 5 shows how a communications apparatus ineach network domain implements uplink data packet forwarding afterreceiving a QoS parameter after division. In FIG. 4 and FIG. 5, acommunications apparatus in a network domain of a RAN is a first accessnetwork device in the RAN, a communications apparatus in a networkdomain of a UPF network element is the UPF network element. For example,in FIG. 4 or FIG. 5, the first access network device may be the accessnetwork device 1 deployed in the RAN in FIG. 1C, the UPF network elementmay be the UPF network element 2 in FIG. 1C, and an application servermay be the application server 8 in FIG. 1C. As shown in FIG. 4, aprocedure for forwarding a downlink data packet includes the followingsteps.

401. The UPF network element receives a downlink data packet from theapplication server.

The downlink data packet includes a first flow identifier. For example,the flow identifier may be a QFI. For example, if the downlink datapacket includes the first flow identifier, the downlink data packet maybe transmitted between a terminal device and the UPF network elementusing a QoS flow identified by the first flow identifier. The user planenetwork element may obtain the first flow identifier corresponding tothe downlink data packet.

402. The UPF network element sends the downlink data packet to the firstaccess network device through a backhaul network based on a QoSparameter that is in first information and that corresponds to the firstflow identifier.

As described above, the UPF network element has obtained firstinformation of a QoS parameter of the domain using the foregoing method,and the first information of the QoS parameter of the domain includes acorrespondence between the first flow identifier and a QoS parameter ofthe network domain of the UPF network element, for example, as shown inTable 7. Therefore, the UPF network element may determine a QoSparameter of the network domain of the UPF network element based on thefirst flow identifier in the downlink data packet and the correspondencebetween the first flow identifier and the QoS parameter of the networkdomain of the UPF network element, and send the downlink data packetbased on the QoS parameter of the network domain of the UPF networkelement.

For example, a time point of receiving the downlink data packet is T1,and the QoS parameter that is in the first information and thatcorresponds to the first flow identifier includes a latency parameter T2and a jitter parameter T3. In this case, the UPF network element maysend the downlink data packet within a time range of T=T1+T2(±)T3.Alternatively, the QoS parameter that is in the first information andthat corresponds to the first flow identifier includes a latencyparameter T4. In this case, the UPF network element may calculate a newbandwidth value based on the latency parameter T4 and with reference toa bandwidth parameter BW, and then send the downlink data packet basedon the new bandwidth value. For example, the new bandwidth value is BW′:BW′=max(BW,(2×BW×T4)/(2×BW+T4)).

In addition, the UPF network element has obtained first information of aQoS parameter of a network domain of the backhaul network using theforegoing method. The first information of the QoS parameter of thenetwork domain of the backhaul network may include a correspondencebetween the first flow identifier and a stream identifier of a secondstream. The second stream is a stream that is in the backhaul networkand that satisfies the QoS parameter of the network domain of thebackhaul network. When forwarding the downlink data packet through thebackhaul network, the UPF network element may add the first flowidentifier and the stream identifier of the second stream to thedownlink data packet based on the correspondence between the first flowidentifier and the stream identifier of the second stream. In this way,after receiving the downlink data packet to which the first flowidentifier and the stream identifier of the second stream are added, thecommunications apparatus in the backhaul network sends, based on thefirst flow identifier and the stream identifier of the second stream,the downlink data packet to the access network device through the secondstream in the backhaul network.

Correspondingly, after receiving the downlink data packet from the UPFnetwork element, the communications apparatus in the backhaul networkmay find a corresponding QoS parameter based on the stream identifier ofthe second stream, and forward the downlink data packet based on the QoSparameter.

403. The first access network device receives the downlink data packetfrom the backhaul network, and sends the downlink data packet to theterminal device based on a QoS parameter that is of the network domainof the RAN and that corresponds to the first flow identifier.

As described above, the first access network device has obtained, usingthe foregoing method, first information of a QoS parameter of the RAN(subsequently, each RAN in which the first access network device islocated is briefly referred to as a first RAN) in which the first accessnetwork device is located, and establishes a corresponding data radiobearer (DRB) for the terminal device. The data radio bearer may schedulea physical resource based on a time-slot. The first information of theQoS parameter of the first RAN includes a correspondence between thefirst flow identifier and a QoS parameter of a first RAN, for example,as shown in the foregoing Table 6. After receiving the downlink datapacket, the first access network device may determine the QoS parameterof the first RAN based on the first flow identifier in the downlink datapacket and the correspondence between the first flow identifier and theQoS parameter of the first RAN, and send the downlink data packet to theterminal device based on the QoS parameter of the first RAN.

Therefore, for the two network domains, the UPF network element and theRAN, precise resource scheduling can be implemented in a correspondingnetwork domain based on a correspondence between a flow identifier and aQoS parameter of the corresponding network domain. For the networkdomain of the backhaul network, precise resource scheduling may also beimplemented in the backhaul network based on a correspondence between aflow identifier and a stream identifier that satisfies a QoS parameterof the domain. Therefore, data packet transmission of a deterministicservice of the terminal device can be ensured.

As shown in FIG. 5, a procedure for forwarding an uplink data packetincludes the following steps.

501. A terminal device sends an uplink data packet to the first accessnetwork device.

The uplink data packet includes a second flow identifier.

502. The first access network device receives the uplink data packetfrom the terminal device, and sends, through a backhaul network, theuplink data packet to the UPF network element based on a QoS parameterthat is in first information and that corresponds to the second flowidentifier.

As described above, the first access network device has obtained firstinformation of a QoS parameter of the first RAN using the foregoingmethod, and first information of the QoS parameter of the domainincludes a correspondence between the second flow identifier and a QoSparameter of a first RAN. Therefore, the first access network device maydetermine the QoS parameter of the first RAN based on the second flowidentifier in the uplink data packet and the correspondence between thesecond flow identifier and the QoS parameter of the first RAN, and sendthe uplink data packet based on the QoS parameter of the first RAN.

In addition, the first access network device has obtained firstinformation of a QoS parameter of the backhaul network using theforegoing method. The first information of the QoS parameter of thebackhaul network may include a correspondence between the second flowidentifier and a stream identifier of a first stream. The first streamis a stream that is in the backhaul network and that satisfies the QoSparameter of the network domain of the backhaul network. Therefore, whenforwarding the uplink data packet through the backhaul network, thefirst access network device may determine the first stream based on thecorrespondence between the second flow identifier and the streamidentifier of the first stream, and then add the stream identifier ofthe first stream to the uplink data packet. In this way, after receivingthe uplink data packet, a communications apparatus in the backhaulnetwork may send the uplink data packet to the UPF network element basedon the second flow identifier and the stream identifier of the firststream using the first stream in the backhaul network.

It can be learned that the UPF network element can implement preciseresource scheduling and data packet forwarding operations based on acorrespondence between a flow identifier and a stream identifier.

503. The UPF network element receives the uplink data packet from thefirst access network device, and obtains the second flow identifier fromthe uplink data packet.

504. The UPF network element sends the uplink data packet to theapplication server based on the QoS parameter that is in the firstinformation and that corresponds to the second flow identifier.

As described above, the UPF network element has obtained firstinformation of a QoS parameter of the network domain of the UPF networkelement using the foregoing method, and the first information of the QoSparameter of the domain includes a correspondence between the secondflow identifier and a QoS parameter of the network domain of the UPFnetwork element. Therefore, the UPF network element may determine theQoS parameter of the network domain of the UPF network element based onthe second flow identifier in the uplink data packet and thecorrespondence between the second flow identifier and the QoS parameterof the network domain of the UPF network element, and send the uplinkdata packet based on the QoS parameter of the network domain of the UPFnetwork element.

It can be learned from the embodiments corresponding to FIG. 4 and FIG.5 that, based on the QoS parameter delivered by the control planenetwork element, both the first access network device and the UPFnetwork element can forward an uplink/downlink data packet based on aprecise QoS parameter, to ensure deterministic transmission.

The following uses an example in which a control plane network elementis an independently deployed deterministic coordinator and capabilityinformation of a backhaul network is stored in a data management networkelement (for example, a UDM), to describe how to assign a QoS parameterto each network domain in a session establishment process. As shown inthe FIG. 6, the procedure may include the following steps.

601. A session management function network element receives a sessionestablishment request from a terminal device.

602. The session management function network element sends asubscription request to the data management network element, to requestto obtain subscription data of the terminal device.

603. The data management network element sends the subscription data ofthe terminal device to the session management function network elementbased on the subscription request.

Correspondingly, the session management function network elementobtains, from the data management network element, the subscription dataof the terminal device. For example, for a feature of the subscriptiondata, refer to the description of the subscription data in FIG. 3A.Details are not described herein again.

604. Execute a session authorization procedure.

For example, the session management function network element mayinteract with another network element on a 3GPP control plane, toperform the session authorization procedure.

605. The session management function network element determines whethera QoS parameter needs to be divided.

For example, when determining that the subscription data includes jitterinformation or a flow identifier of a service flow of a deterministicservice, the session management function network element determines thatthe QoS parameter needs to be divided. For step 605, refer to thedescription of step 302 in FIG. 3A. Details are not described hereinagain.

606. The session management function network element sends a divisionrequest to the deterministic coordinator.

The division request carries a first QoS parameter, an IP address of anaccess network device, and an IP address of a UPF network element.

Accordingly, the deterministic coordinator receives the division requestfrom the session management function network element.

607 a. The deterministic coordinator sends a backhaul network capabilityrequest to the data management network element, to request to obtain thecapability information of the backhaul network.

608 a. The deterministic coordinator receives the capability informationof the backhaul network from the data management network element.

In another embodiment, if a network management network element sends thecapability information of the backhaul network to the deterministiccoordinator in a configuration phase of the backhaul network, step 607 aand step 608 a may be omitted.

607 b. The deterministic coordinator separately sends a request messageto a first access network device and the UPF network element, where therequest message carries a transmit frequency and a size of a datapacket.

608 b. The deterministic coordinator receives capability information ofa wireless network domain from the first access network device.

608 c. The deterministic coordinator receives, from the UPF networkelement, capability information of the UPF network element.

For the capability information of the backhaul network, capabilityinformation of the RAN, and the capability information of the UPFnetwork element that are obtained in the foregoing steps, refer todescriptions in FIG. 3A. Similar content is not described in detailagain.

609. The deterministic coordinator divides the first QoS parameter basedon the capability information of the RAN, the capability information ofthe UPF network element, and the capability information of the backhaulnetwork, to obtain a QoS parameter corresponding to each network domain,where the QoS parameter obtained after the division corresponds to onenetwork domain (or two network domains).

610. The deterministic coordinator sends first information of the QoSparameter obtained after the division.

For step 610, refer to the description of step 303 in FIG. 3A. Detailsare not described herein again.

For example, for the RAN, the deterministic coordinator may send, usinga session establishment response, the first information of the QoSparameter obtained after the division. However, this application is notlimited thereto. The deterministic coordinator may alternativelytransmit, using another message, the first information of the QoSparameter obtained after the division. In addition, for the UPF networkelement, the deterministic coordinator may alternatively transmit, usinga newly added message or any existing message, the first information ofthe QoS parameter obtained after the division.

It should be noted that, if the control plane network element is an SMFinto which a deterministic coordination function is integrated, thecontrol plane network element may implement all steps that are the sameas or similar to those of the session management function networkelement and the deterministic coordinator in FIG. 6, and interactionbetween the session management function network element and thedeterministic coordinator (for example, step 606) may be omitted.

With reference to the example in FIG. 6, the communications apparatus,in the first network domain, that performs the method in FIG. 3B may bea first RAN or the UPF network element. Therefore, in the sessionestablishment phase, the deterministic coordinator may divide anend-to-end QoS parameter between the terminal device and the UPF networkelement based on capability information of each network domain.

For example, after the deterministic service of the terminal device hasbeen running for a period of time, a QoS parameter of a network domainmay not satisfy the current deterministic service. For example, whencapability information of the access network device or the UPF networkelement fluctuates (for example, a quantity of accessed terminal deviceschanges or a location of the terminal device changes), the accessnetwork device cannot provide the terminal device with a data radiobearer that satisfies a QoS parameter corresponding to the service. Theaccess network device needs to switch the deterministic service of theterminal device to a new access network device. Because the backhaulnetwork between the terminal device and the UPF network element changesbefore the switching, the deterministic coordinator further needs todynamically adjust the QoS parameter. For example, the deterministiccoordinator re-divides the QoS parameter for each network domain. Forexample, the new access network device may obtain an updated more looseQoS parameter (for example, a latency indicator or a jitter indicator)from the deterministic coordinator, ensuring stability of thedeterministic service after the switching. The following describes,based on a scenario of handover between access network devices, aprocess in which a deterministic coordinator dynamically adjusts a QoSparameter of a first network domain.

FIG. 7 and FIG. 8 each describe a process in which a deterministiccoordinator determines a QoS parameter of each network domain in ahandover scenario in which a terminal device is handed over from a firstaccess network device to a second access network device. Before thehandover, the terminal device accesses a core network using the firstaccess network device, after the handover, the terminal device accessesthe core network using the second access network device. Before theterminal device is handed over from the first access network device tothe second access network device, capability information of a first RANin which the first access network device is located is considered fordividing a QoS parameter between the terminal device and a UPF networkelement by the deterministic coordinator. For example, according to themethod shown in FIG. 6, the deterministic coordinator divides the QoSparameter between the terminal device and the UPF network element basedon the capability information of the first RAN and capabilityinformation of another network domain. If the terminal device needs tobe handed over to the second access network device, the second accessnetwork device sends capability information of a second RAN to a controlplane network element, to trigger the deterministic coordinator tore-divide the QoS parameter between the terminal device and the UPFnetwork element based on the capability information fed back by thesecond access network device.

In an example in FIG. 7, the method includes the following steps.

701. The first access network device sends a measurement control messageto the terminal device.

After receiving the measurement control message, the terminal deviceperforms measurement and generates a measurement report.

702. The first access network device receives a measurement report sentby the terminal device, where the measurement report includes signalquality of a neighboring cell.

703. The first access network device sends a handover request to thesecond access network device when determining, based on the measurementreport, that the terminal device satisfies a handover condition.

The handover request carries a QoS parameter of the first RAN and atransmit frequency and a size of a data packet.

704. When the second access network device determines, based on the QoSparameter of the first RAN and the transmit frequency and the size ofthe data packet, that the second access network device currently meets acondition for creating a data radio bearer that satisfies the QoSparameter of the first RAN and the transmit frequency and the size ofthe data packet, the second access network device creates the data radiobearer that satisfies the QoS parameter of the first RAN and thetransmit frequency and the size of the data packet.

For example, the second access network device learns, based on thetransmit frequency and the size of the data packet, of the capabilityinformation of the second RAN in which the second access network deviceis located, and determines, based on the capability information of thesecond RAN and the QoS parameter of the first RAN, whether a capabilityof the second RAN after handover can satisfy the QoS parameter of thefirst RAN before handover. If the capability satisfies the QoSparameter, the data radio bearer that satisfies the QoS parameter of thefirst RAN and the transmit frequency and the size of the data packet iscreated.

If the capability of the second RAN after handover can satisfy the QoSparameter of the first RAN before handover, it indicates that the secondRAN after handover may use a QoS parameter the same as that of the firstRAN before handover, that is, the QoS parameter of the first RAN is theQoS parameter of the second RAN.

705. The second access network device sends the QoS parameter of thesecond RAN, an IP address of the second access network device, and an IPaddress of the UPF network element to the deterministic coordinator.

The IP address of the second access network device and the IP address ofthe UPF network element are used to identify a backhaul network betweenthe second access network device and the UPF network element. Afterreceiving the IP address of the second access network device and the IPaddress of the UPF network element, the deterministic coordinator maydetermine the backhaul network between the second access network deviceand the UPF network element, to obtain, locally or from a datamanagement network element, capability information of the backhaulnetwork.

Optionally, in step 705, the second access network device may furthersend the transmit frequency and the size of the data packet to thedeterministic coordinator. After receiving the transmit frequency andthe size of the data packet, the deterministic coordinator may send thetransmit frequency and the size of the data packet to the UPF networkelement based on the IP address of the UPF network element, to requestto obtain capability information of the UPF network element. In anotherembodiment, the second access network device may alternatively locallyobtain previously stored capability information of the UPF networkelement. In this case, the transmit frequency and the size of the datapacket may not be sent in step 705.

In addition, because the second access network device can create thedata radio bearer, and the second RAN in which the second access networkdevice is located can satisfy a requirement of the terminal device, thesecond access network device may request the control plane networkelement to reassign only a QoS parameter of the backhaul network and aQoS parameter of the UPF network element.

706. The deterministic coordinator reassigns QoS parameters to thebackhaul network and the UPF network element based on the QoS parameterof the second RAN, the capability information of the backhaul networkbetween the second access network device and the UPF network element,and the capability information of the UPF network element.

The QoS parameter may alternatively be re-divided in the manner in step302 in FIG. 3A. Details are not described herein again.

707. The deterministic coordinator delivers information about the QoSparameters obtained after re-division.

The information about the QoS parameters obtained after division may beimplemented in a manner similar to that for the first information of thesecond QoS parameter in FIG. 3A. Details are not described herein again.

In addition, a transmission stream between the terminal device and theUPF network element changes after the terminal device is handed overfrom the first access network device to the second access networkdevice. Therefore, to ensure normal running of the deterministic serviceof the terminal device, the control plane network element may furtherupdate a correspondence between a flow identifier and a QoS parameter,and separately deliver an updated correspondence to the second accessnetwork device and the UPF network element.

Then, the terminal device is handed over from the first access networkdevice to the second access network device.

It can be learned that, considering that the transmission stream betweenthe terminal device and the UPF network element changes after theterminal device is handed over from the first access network device tothe second access network device, the deterministic coordinator canre-divide corresponding QoS parameters for the second RAN in which thesecond access network device is located, the UPF network element, andthe backhaul network between the second access network device and theUPF network element. Therefore, after the terminal device is handed overto the second access network device, each network domain can stillperform pertinent and precise determining and scheduling.

FIG. 8 shows another method. A difference between FIG. 8 and FIG. 7 liesin that, in the example in FIG. 8, the second access network device doesnot need to determine whether the second RAN in which the second accessnetwork device is located satisfies the QoS parameter of the first RAN.For example, the method includes the following steps.

801. The first access network device sends a measurement control messageto the terminal device.

After receiving the measurement control message, the terminal deviceperforms measurement and generates a measurement report.

802. The first access network device receives the measurement reportsent by the terminal device. The measurement report includes signalquality of a neighboring cell.

803. The first access network device sends a handover request to thesecond access network device when determining, based on the measurementreport, that the terminal device satisfies a handover condition.

The handover request includes a transmit frequency and a size of a datapacket.

804. After receiving the handover request, the second access networkdevice may determine, based on the transmit frequency and the size ofthe data packet, the capability information of the second RAN in whichthe second access network device is located.

805. The second access network device sends the capability informationof the second RAN, an IP address of the second access network device,and an IP address of the UPF network element to the deterministiccoordinator.

The IP address of the second access network device and the IP address ofthe UPF network element are used to identify a backhaul network betweenthe second access network device and the UPF network element. Afterreceiving the IP address of the second access network device and the IPaddress of the UPF network element, the deterministic coordinator maydetermine the backhaul network between the second access network deviceand the UPF network element, to obtain, locally or from a datamanagement network element, capability information of the backhaulnetwork.

Optionally, in step 805, the second access network device may furthersend the transmit frequency and the size of the data packet to thedeterministic coordinator. After receiving the transmit frequency andthe size of the data packet, the deterministic coordinator may send thetransmit frequency and the size of the data packet to the UPF networkelement based on the IP address of the UPF network element, to requestto obtain capability information of the UPF network element. In anotherembodiment, the second access network device may alternatively locallyobtain previously stored capability information of the UPF networkelement. In this case, the transmit frequency and the size of the datapacket may not be sent in step 805.

806. The deterministic coordinator re-divides the QoS parameter for eachnetwork domain based on the capability information of the second RAN,the capability information of the backhaul network between the secondaccess network device and the UPF network element, and the capabilityinformation of the UPF network element.

The QoS parameter may alternatively be re-divided in the manner in step302 in FIG. 3A. Details are not described herein again.

807. The deterministic coordinator delivers information about the QoSparameters obtained after re-division.

The information about the QoS parameters obtained after division may beimplemented in a manner similar to that for the first information of thesecond QoS parameter in FIG. 3A. Details are not described herein again.

Similarly, a transmission stream between the terminal device and the UPFnetwork element changes after the terminal device is handed over fromthe first access network device to the second access network device.Therefore, to ensure normal running of the deterministic service of theterminal device, the control plane network element may further update acorrespondence between a flow identifier and a QoS parameter, andseparately deliver an updated correspondence to the second accessnetwork device and the UPF network element.

Then, the terminal device is handed over from the first access networkdevice to the second access network device.

With reference to the example in FIG. 8, the communications apparatus,of the first network domain, that performs the method in FIG. 3B may bean access network device (namely, the second access network device) in aRAN (namely, the second RAN) after handover. In a handover phase, afterreceiving the handover request from the first access network devicebefore handover, the second access network device sends the capabilityinformation of the second RAN to the deterministic coordinator such thatthe deterministic coordinator re-divides the end-to-end QoS parameterbetween the terminal device and the UPF network element based on thecapability information of the second RAN.

In this embodiment of this application, after the terminal device ishanded over from the first access network device to the second accessnetwork device, the transmission stream between the terminal device andthe UPF network element changes. The deterministic coordinator canre-divide corresponding QoS parameters for the second RAN in which thesecond access network device is located, the UPF network element, andthe backhaul network between the second access network device and theUPF network element. Compared with an existing mechanism in which eachnetwork domain can be scheduled based on only an end-to-end QoSparameter, in this embodiment of this application, the second accessnetwork device and the UPF network element can obtain a dynamicallyadjusted QoS parameter, and perform precise scheduling based on QoSparameters of respective domains, ensuring deterministic transmissionand resource utilization.

It should be noted that, after step 703 in FIG. 7, if the second accessnetwork device determines that the second access network devicecurrently does not meet a condition for creating a data radio bearerthat satisfies the QoS parameter of the first RAN and the transmitfrequency and the size of the data packet, a QoS parameter re-divisionprocedure may alternatively be completed in a manner similar to that ofsteps 805 to 807 in FIG. 8.

Technical features, such as the capability information of each networkdomain, the QoS parameter assigned to each network domain, and thecorrespondence indicating the QoS parameter assigned to each networkdomain, that are described in the foregoing embodiments are alsoapplicable to the embodiment corresponding to any one of FIG. 9 to FIG.15 in this application. Subsequent similar content is not described indetail again.

The following separately describes the control plane network element,the communications apparatus, and the session management functionnetwork element that are configured to perform the QoS parameterprocessing method, and the network management network element and thenetwork configuration network element that are configured to perform thenetwork management method.

Referring to a control plane network element 90 shown in FIG. 9, thecontrol plane network element 90 may be configured to process a QoSparameter, and the control plane network element 90 can implement a QoSparameter processing step performed by the control plane network elementin the embodiment corresponding to any one of FIG. 3A to FIG. 8. Afunction implemented by the control plane network element 90 may beimplemented by hardware, or may be implemented by hardware by executingcorresponding software. The hardware or software includes one or moremodules corresponding to the function. The module may be software and/orhardware. The control plane network element 90 may be an independentlydeployed network element, or may be a logical network element integratedin a session management function network element or another 3GPP networkelement. This is not limited. The control plane network element 90 mayinclude a transceiver module and a processing module. For functionimplementation of the processing module, refer to operations ofdetermining the QoS parameter of the first network domain, determiningwhether the second access network device satisfies the requirement ofthe deterministic service of the terminal device, and dynamicallyadjusting the QoS parameter of the first network domain by the controlplane network element in the embodiment corresponding to any one of FIG.3A to FIG. 8. Details are not described herein again. For functionimplementation of the transceiver module, refer to operations ofobtaining the capability information of the first network domain, anddelivering the first information of the QoS parameter of the firstnetwork domain by the control plane network element in the embodimentcorresponding to any one of FIG. 3A to FIG. 8. The processing module 902may be configured to control receiving and sending operations of thetransceiver module.

In some implementations, the transceiver module 901 may be configured toobtain a first QoS parameter between a terminal device and a UPF networkelement, and obtain capability information of a first network domain,the processing module 902 is configured to determine a second QoSparameter of the first network domain based on the capabilityinformation of the first network domain and the first QoS parameter thatare obtained by the transceiver module, where the first network domainincludes at least one of a RAN, a backhaul network, and the UPF networkelement, and the transceiver module 901 is further configured to sendfirst information of the second QoS parameter to the first networkdomain.

In this embodiment of this application, the processing module 902 in thecontrol plane network element 90 can determine the second QoS parameterof the first network domain (that is, determines a QoS parameter of atleast one network domain) based on the capability information of thefirst network domain and the first QoS parameter, to be specific,separately assigns a proper QoS parameter to each network domain, andthen separately delivers the QoS parameter to each network domain,ensuring that the QoS parameter obtained by each network domain is a QoSparameter of the corresponding network domain. Compared with an existingmechanism in which each network domain can be scheduled based on only anend-to-end indicator, in this embodiment of this application, acommunications apparatus in each network domain can perform precisescheduling based on the QoS parameter of the corresponding networkdomain, improving user experience. In addition, deterministictransmission can be ensured, and resource utilization can be improved.

In some implementations, when the first network domain includes the RANor the UPF network element, the transceiver module 901 is configured tosend a transmit frequency and a size of a data packet to the firstnetwork domain, and receive the capability information of the firstnetwork domain from the first network domain, where the capabilityinformation of the first network domain is associated with the transmitfrequency and the size of the data packet.

In some implementations, when the first network domain includes the RANor the UPF network element, the first information includes acorrespondence between a flow identifier and the second QoS parameter,and the flow identifier is used to identify a QoS flow between theterminal device and the UPF network element.

In some implementations, when the first network domain includes thebackhaul network, the transceiver module 901 is configured to receive,from a network management network element, capability information of thebackhaul network, or obtain, from a data management network element,capability information of the backhaul network.

In some implementations, the capability information of the backhaulnetwork includes a stream identifier of a service flow in the backhaulnetwork, a quantity of available service flows, and a QoS parameter ofthe service flow.

In some implementations, the first information includes a correspondencebetween a flow identifier and a stream identifier, the flow identifieris used to identify a QoS flow between the terminal and the UPF networkelement, and the stream identifier is used to identify a stream that isin the backhaul network and that satisfies the second QoS parameter.

In some implementations, the processing module 902 is further configuredto obtain subscription data of the terminal device using the transceivermodule 901, and when the subscription data includes second informationused to indicate that a service of the terminal device includes adeterministic service, determine the second QoS parameter of the firstnetwork domain based on the capability information of the first networkdomain and the first QoS parameter.

In some implementations, the processing module 902 is configured todetermine the second QoS parameter for the first network domain based onthe capability information of the first network domain, the first QoSparameter, and a priority of the first network domain.

In addition, the transceiver module 901 and the processing module 902 inthe control plane network element 90 may further perform another stepperformed by the deterministic coordinator or the control plane networkelement in any one of the embodiments of FIG. 3A to FIG. 8. Details arenot described herein again.

Referring to a communications apparatus shown in FIG. 10, thecommunications apparatus can process a QoS parameter, and thecommunications apparatus 100 can implement a QoS parameter processingstep that is performed by the communications apparatus of the firstnetwork domain in the embodiment corresponding to any one of FIG. 4 toFIG. 8. A function implemented by the communications apparatus 100 maybe implemented by hardware, or may be implemented by hardware byexecuting corresponding software. The hardware or software includes oneor more modules corresponding to the function. The module may besoftware and/or hardware. The communications apparatus 100 may be a UPFnetwork element, or may be an access network device in a RAN domain.This is not limited. The communications apparatus 100 may include atransceiver module 1001 and a processing module 1002. The processingmodule 1002 may be configured to control receiving and sendingoperations of the transceiver module 1001. For function implementationof the transceiver module 1001, refer to operations of sending the QoSparameter of the first network domain, the capability information of thefirst network domain, and the transmit frequency and the size of thedata packet to the control plane network element or the sessionmanagement function network element by the communications apparatus inthe embodiment corresponding to any one of FIG. 4 to FIG. 8. Details arenot described herein again.

In some implementations, the transceiver module 1001 is configured tosend capability information of the first network domain to a controlplane network element, where the capability information of the firstnetwork domain is used to determine a QoS parameter of the first networkdomain, and the first network domain includes a RAN or a UPF networkelement, and receive, from the control plane network element, firstinformation of the QoS parameter of the first network domain.

In this embodiment of this application, the processing module 1002 inthe communications apparatus 100 in the first network domain providesthe capability information of the first network domain for the controlplane network element such that the control plane network element canaccurately determine the QoS parameter of the first network domain, andthe communications apparatus of the first network domain obtains, fromthe control plane network element, the QoS parameter of the firstnetwork domain. Therefore, a communications apparatus in a networkdomain can perform precise scheduling based on a QoS parameter of thisnetwork domain, improving user experience. In addition, deterministictransmission can be ensured, and resource utilization can be improved.

In some implementations, the first information includes a correspondencebetween a flow identifier and the QoS parameter, and the flow identifieris used to identify a QoS flow between the terminal device and the UPFnetwork element.

In some implementations, when the first network domain includes the RAN,the communications apparatus is a first access network device in theRAN, and the transceiver module 1001 is further configured to perform atleast one of the following operations receiving a downlink data packetfrom the UPF network element, where the downlink data packet includes afirst flow identifier, and sending the downlink data packet to theterminal device based on a QoS parameter that is in the firstinformation and that corresponds to the first flow identifier, orreceiving an uplink data packet from the terminal device, where theuplink data packet includes a second flow identifier, and sending,through a backhaul network, the uplink data packet to the UPF networkelement based on a QoS parameter that is in the first information andthat corresponds to the second flow identifier.

In some implementations, the transceiver module 1001 is configured toreceive, from the control plane network element, a correspondencebetween the second flow identifier and a stream identifier of a firststream, and send the uplink data packet to the UPF network element basedon the correspondence between the second flow identifier and the streamidentifier of the first stream using the first stream in the backhaulnetwork.

In some implementations, when the first network domain includes the UPFnetwork element, the communications apparatus is the UPF networkelement, and the transceiver module 1001 is further configured toperform at least one of the following operations receiving a downlinkdata packet from an application server, where the downlink data packetincludes a first flow identifier, and sending, through the backhaulnetwork, the downlink data packet to the first access network devicebased on a QoS parameter that is in the first information and thatcorresponds to the first flow identifier, or receiving an uplink datapacket from an access network device, where the uplink data packetincludes a second flow identifier, and sending the uplink data packet toan application server based on a QoS parameter that is in the firstinformation and that corresponds to the second flow identifier.

In some implementations, the transceiver module 1001 is configured toreceive, from the control plane network element, a correspondencebetween the first flow identifier and a stream identifier of a secondstream, and send the downlink data packet to the first access networkdevice based on the correspondence between the first flow identifier andthe stream identifier of the second stream using the second stream inthe backhaul network.

In addition, the transceiver module 1001 and the processing module 1002in the communications apparatus 10 may further perform another stepperformed by the communications apparatus (for example, a communicationsapparatus in the UPF network element, the first access network device,the second access network device, or the backhaul network) of the firstnetwork domain in any one of the embodiments of FIG. 3A to FIG. 8.Details are not described herein again.

Referring to a session management function network element 110 shown inFIG. 11, the session management function network element 110 may beconfigured to process a QoS parameter. The session management functionnetwork element 110 can implement a QoS parameter processing stepperformed by the session management function network element in theembodiment corresponding to any one of FIG. 4 to FIG. 8. A functionimplemented by the session management function network element 110 maybe implemented by hardware, or may be implemented by hardware byexecuting corresponding software. The hardware or software includes oneor more modules corresponding to the function. The module may besoftware and/or hardware. A control plane network element may bedeployed in the session management function network element 110, toimplement all functions that are the same as or similar to those of thecontrol plane network element 90. This is not limited. The sessionmanagement function network element 110 may include a transceiver module1101 and a processing module 1102. For function implementation of theprocessing module 1102, refer to operations of determining whether thesubscription data includes the second information that indicates thedeterministic service, determining whether the second access networkdevice satisfies the requirement of the deterministic service of theterminal device, and dynamically adjusting the QoS parameter of thefirst network domain by the session management function network element110 in the embodiment corresponding to any one of FIG. 4 to FIG. 8.Details are not described herein. For function implementation of thetransceiver module 1101, refer to operations of obtaining thesubscription data of the terminal device, obtaining the capabilityinformation of the first network domain, and delivering the firstinformation of the QoS parameter of the first network domain in theembodiment corresponding to any one of FIG. 4 to FIG. 8.

In some implementations, the transceiver module 1101 may be configuredto obtain the subscription data of the terminal device from a datamanagement network element, and the processing module 1102 may beconfigured to, when the subscription data includes information used toindicate that a service of the terminal device includes a deterministicservice, send a request message to the control plane network elementusing the transceiver module 1101, where the request message is used torequest to determine the QoS parameter of the first network domain, andthe first network domain includes at least one of a RAN, a backhaulnetwork, and a UPF network element.

In some implementations, the transceiver module 1101 is furtherconfigured to obtain capability information of the backhaul network fromthe data management network element, or receive capability informationof the backhaul network from a network management network element.

In this embodiment of this application, the processing module 1102 inthe session management function network element 110 obtains thesubscription data from the data management network element, determines,based on the subscription data, whether the terminal device has thedeterministic service, and then determines whether to send, to thecontrol plane network element, the request message for determining theQoS parameter of the first network domain. In this way, work load of thecontrol plane network element can be reduced, and a work divisionmechanism can also be optimized.

In addition, the transceiver module 1101 and the processing module 1102in the session management function network element 110 may furtherperform another step performed by the control plane network element inany one of the embodiments of FIG. 3A to FIG. 8. Details are notdescribed herein again.

Referring to a network management network element 120 shown in FIG. 12,the network management network element 120 can implement a networkmanagement step performed by the network management network element inthe embodiment corresponding to FIG. 2. A function implemented by thenetwork management network element 120 may be implemented by hardware,or may be implemented by hardware by executing corresponding software.The hardware or software includes one or more modules corresponding tothe function. The module may be software and/or hardware. The networkmanagement network element 120 may be the network management networkelement 5 in FIG. 1C, and is configured to manage a backhaul network.The network management network element 120 may include a transceivermodule 1201 and a processing module 1202. The processing module 1202 maybe configured to control receiving and sending operations of thetransceiver module 1201. For function implementation of the transceivermodule 1201, refer to operations of sending the configuration request tothe backhaul network configuration network element and sending thecapability information of the backhaul network to the data managementnetwork element by the network management network element in theembodiment corresponding to FIG. 2. Details are not described herein.

The transceiver module 1201 is configured to send the configurationrequest to the backhaul network configuration network element, where theconfiguration request is used to request to configure the capabilityinformation of the backhaul network, and receive the capabilityinformation of the backhaul network from the backhaul networkconfiguration network element, and send the capability information ofthe backhaul network to the data management network element.

In this embodiment of this application, interaction between a networkconfiguration network element 130 in FIG. 13 and the data managementnetwork element ensure that the capability information of the backhaulnetwork can be transmitted to the data management network element, andsubsequently the control plane network element uses the capabilityinformation of the backhaul network as a basis for determining a QoSparameter of each network domain.

In addition, the transceiver module 1201 and the processing module 1202in the network management network element 120 may further performanother step performed by the network management network element in theembodiment corresponding to FIG. 2. Details are not described hereinagain.

Referring to a network configuration network element shown in FIG. 13,the network configuration network element 130 can implement a networkmanagement step performed by the backhaul network configuration networkelement in the embodiment corresponding to FIG. 2. A functionimplemented by the network configuration network element 130 may beimplemented by hardware, or may be implemented by hardware by executingcorresponding software. The hardware or software includes one or moremodules corresponding to the function. The module may be software and/orhardware. The network configuration network element 130 may be thebackhaul network configuration network element 6 in FIG. 1C, and isconfigured to configure the backhaul network. The network managementnetwork element 130 may include a transceiver module 1301 and aprocessing module 1302. The processing module 1302 may be configured tocontrol receiving and sending operations of the transceiver module 1301.For function implementation of the transceiver module, refer tooperations of configuring the backhaul network and the capabilityinformation of the backhaul network, and sending the capabilityinformation of the backhaul network to the network management networkelement by the backhaul network configuration network element in theembodiment corresponding to FIG. 2. Details are not described herein.

In some implementations, the transceiver module 1301 may be configuredto receive a configuration request from the network management networkelement, and the processing module 1302 may be configured to configurethe capability information of the backhaul network based on theconfiguration request, and send the capability information of thebackhaul network to the network management network element using thetransceiver module 1301.

In some implementations, the configuration request may include anexpected value of a QoS parameter of a first network domain, an IPaddress of an access network device, and an IP address of a UPF networkelement.

In this embodiment of this application, after the transceiver module1301 receives the configuration request from the network managementnetwork element, the processing module of the network configurationnetwork element 130 interacts with the network management networkelement such that the capability information of the backhaul network canbe transmitted to the network management network element, andsubsequently the control plane network element uses the capabilityinformation, of the backhaul network, obtained from the data managementnetwork element as a basis for determining the QoS parameter of eachnetwork domain.

In addition, the transceiver module 1301 and the processing module 1302in the network configuration network element 130 may further performanother step performed by the backhaul network configuration networkelement in the embodiment corresponding to FIG. 2. Details are notdescribed herein again.

Referring to a communications system shown in FIG. 15, thecommunications system may include a terminal device, the control planenetwork element 90 shown in FIG. 9, and the communications apparatus 100shown in FIG. 10 in each network domain.

For example, the communications apparatus 100 may be configured toprovide the control plane network element 90 with capability informationof a first network domain.

The control plane network element 90 is configured to obtain a first QoSparameter between the terminal device and a UPF network element, obtaincapability information of each network domain, determine a second QoSparameter of each network domain based on the capability information ofeach network domain and the first QoS parameter, and send firstinformation of the second QoS parameter to each network domain using thetransceiver module. Network domains may include a RAN, a backhaulnetwork, and the UPF network element.

In some implementations, the communications system may further includethe network management network element 120 shown in FIG. 12, the networkconfiguration network element 130 shown in FIG. 13, and the datamanagement network element. The data management network element isconfigured to store the capability information, of the backhaul network,from the network configuration network element 130 shown in FIG. 13.

In some implementations, the communications system may further includethe session management function network element 110 shown in FIG. 11.

In the embodiments of this application (including the embodiments shownin FIG. 9 to FIG. 13), entity devices corresponding to the transceivermodules (for example, the transceiver module 901, the transceiver module1001, the transceiver module 1101, the transceiver module 1201, and thetransceiver module 1301) may be the transceiver 1501, and entity devicescorresponding to the processing modules (for example, the processingmodule 902, the processing module 1002, the processing module 1102, theprocessing module 1202, and the processing module 1302) may be theprocessor 1502. The apparatuses shown in FIG. 9 to FIG. 13 may each havethe structure shown in FIG. 15. When one of the apparatuses has thestructure shown in FIG. 15, the processor 1501 and the transceiver 1502in FIG. 15 implement functions that are the same as or similar to thoseof the processing module (for example, the processing module 902, theprocessing module 1002, the processing module 1102, the processingmodule 1202, or the processing module 1302) and the transceiver module(for example, the transceiver module 901, the transceiver module 1001,the transceiver module 1101, the transceiver module 1201, or thetransceiver module 1301) that are provided in the foregoing apparatusembodiment corresponding to the apparatus.

For example, when the control plane network element has the structureshown in FIG. 15, the memory 1503 in FIG. 15 stores program code thatneeds to be invoked when the processor 1502 performs the foregoing QoSparameter processing method performed by the control plane networkelement. Alternatively, a computer-readable storage medium 1504 storesprogram code that needs to be invoked when the control plane networkelement performs the foregoing QoS parameter processing method. Theprocessor 1502 in FIG. 15 can invoke the program code in the memory 1503or the computer-readable storage medium 1504 to perform the followingoperations obtaining a first QoS parameter between a terminal device anda UPF network element using the transceiver 1501, and obtainingcapability information of a first network domain, determining a secondQoS parameter of the first network domain based on the capabilityinformation of the first network domain and the first QoS parameter thatare obtained by the transceiver 1501, where the first network domainincludes at least one of a RAN, a backhaul network, and the UPF networkelement, and sending first information of the second QoS parameter tothe first network domain using the transceiver 1501.

For another example, when the communications apparatus of the firstnetwork domain has the structure shown in FIG. 15, the memory in FIG. 15stores program code that needs to be invoked when the processor performsthe foregoing QoS parameter processing method performed by thecommunications apparatus of the first network domain in the embodimentcorresponding to any one of FIG. 4 to FIG. 8. Further, the processor1502 in FIG. 15 can invoke the program code in the memory 1503 or thecomputer-readable storage medium 1504 to perform the followingoperations sending capability information of the first network domain toa control plane network element using the transceiver 1501, where thecapability information of the first network domain is used to determinea QoS parameter of the first network domain, and the first networkdomain includes a RAN or a UPF network element, and receiving, from thecontrol plane network element, first information of the QoS parameter ofthe first network domain using the transceiver 1501.

For another example, when the communications apparatus of the firstnetwork domain has the structure shown in FIG. 15, the memory in FIG. 15stores program code that needs to be invoked when the processor performsthe foregoing QoS parameter processing method performed by the sessionmanagement function network element in the embodiment corresponding toany one of FIG. 4 to FIG. 8. Further, the processor 1502 in FIG. 15 caninvoke the program code in the memory 1503 or the computer-readablestorage medium 1504 to perform the following operations obtainingsubscription data of a terminal device from a data management networkelement using the transceiver 1501, and when the subscription dataincludes information used to indicate that a service of the terminaldevice includes a deterministic service, sending a request message to acontrol plane network element using the transceiver 1501, where therequest message is used to request to determine a QoS parameter of thefirst network domain, and the first network domain includes at least oneof a RAN, a backhaul network, and a UPF network element.

Other cases are similar, and details are not described.

In addition, an embodiment of this application further discloses anothermethod for dividing a QoS parameter an end-to-end QoS parameter) betweena terminal device and a UPF network element by a control plane networkelement. The QoS parameter between the terminal device and the UPFnetwork element is divided into a QoS parameter between the terminaldevice and an access network device and a QoS parameter between theaccess network device and the UPF network element. An example in whichthe QoS parameter is a packet delay budget (PDB) is used. In a currentQoS model, the PDB is an upper limit of a delay for transmission of adata packet between the terminal device and the UPF network element (aUPF terminating an N6 interface). For example, for a QoS flow, a valueof a PDB between UE and a UPF is 5 ms. According to the method in thisembodiment of this application, after the PDB value is divided, a PDBbetween an AN and the UPF is 2 ms, and a PDB between the UE and the ANis 3 ms such that the AN can schedule an air interface resource based ona requirement for a 3 ms PDB. In this way, a URLLC service latencyrequirement is ensured, and utilization of an air interface resource canalso be optimized. Detailed descriptions are provided below.

FIG. 16A is a schematic flowchart of a QoS parameter processing methodaccording to an embodiment of this application. As shown in FIG. 16A,this method includes the following steps.

Step 1601: A control plane network element obtains a first QoS parameterbetween a first access network device and a first UPF network element.

For example, the control plane network element may be the foregoingsession management function SMF network element 7 in FIG. 1C. The firstaccess network device may be the access network device 1 in FIG. 1C. Thefirst UPF network element may be the UPF network element 2 in FIG. 1C.

The first QoS parameter between the first access network device and thefirst UPF network element may also be referred to as a QoS parameter ofa core network (CN). For example, the first QoS parameter includes a PDBbetween the first access network device and the UPF network element, forexample, a CN PDB.

The control plane network element may obtain the first QoS parameterbetween the first access network device and the first UPF networkelement in any one of the following manners.

Manner 1: The control plane network element obtains the first QoSparameter from the first UPF network element.

For example, the control plane network element sends identifierinformation of the first access network device to the first UPF networkelement, and receives the first QoS parameter from the first UPF networkelement. Optionally, the control plane network element further sendsflow information that identifies a first flow to the first UPF networkelement such that the first QoS parameter indicates a QoS parameter thatis between the first access network device and the first UPF networkelement and that corresponds to the first flow. How the control planenetwork element obtains the first QoS parameter from the first UPFnetwork element is further described with reference to FIG. 17.

Manner 2: The control plane network element obtains the first QoSparameter from a network element discovery function device.

The network element discovery function device may be a networkrepository function (NRF) network element. The NRF network element mayprovide functions such as network function instance registration anddiscovery.

For example, in a possible implementation, the control plane networkelement sends identifier information of the first access network deviceand identifier information of the first UPF network element to the NRFnetwork element, and receives the first QoS parameter from the NRFnetwork element.

In another possible implementation, the control plane network elementsends identifier information of the first access network device andservice area information of the control plane network element to the NRFnetwork element, and receives, from the NRF network element, identifierinformation of at least one UPF network element located in an areaindicated by the service area information, and a QoS parameter betweenthe first access network device and each of the at least one UPF networkelement, and the control plane network element determines the first QoSparameter according to the received QoS parameter.

In another possible implementation, the control plane network elementsends service area information of the control plane network element tothe NRF network element, and receives, from the NRF network element,identifier information of at least one UPF network element located in anarea indicated by the service area information, identifier informationof an access network device that communicates with each of the at leastone UPF network element, and a QoS parameter between each of the atleast one UPF network element and the access network device, and thecontrol plane network element determines the first QoS parameteraccording to the received QoS parameter based on identifier informationof the first access network device.

How the control plane network element obtains the first QoS parameterfrom the network element discovery function device is further describedwith reference to FIG. 18A and FIG. 18B.

Manner 3: The control plane network element obtains the first QoSparameter from a network management system.

For example, when the control plane network element is powered on, thecontrol plane network element obtains the first QoS parameter from thenetwork management system. For example, when the control plane networkelement is powered on, the network management system configures thefirst QoS parameter for the control plane network element.Alternatively, after the control plane network element is powered on,the control plane network element may actively send a request to thenetwork management system, to request to obtain a QoS parameter betweeneach of at least one UPF network element in a service area of thecontrol plane network element and an access network device. The controlplane network element determines the first QoS parameter according tothe received the QoS parameter based on identifier information of thefirst access network device.

How the control plane network element obtains the first QoS parameterfrom the network management system is further described with referenceto FIG. 19.

Manner 4: The control plane network element obtains the first QoSparameter from a network data analytics function device.

A network data analytics function device (NWDAF) network element mayprovide a data analysis result related to a network and a user.

For example, the NWDAF network element may obtain information about atransmission latency between the first access network device and theuser plane network element from a collected QoS monitoring result,generate the first QoS parameter after performing a statisticalanalysis, and provide the first QoS parameter for the control planenetwork element.

Step 1602: The control plane network element determines a third QoSparameter between the terminal device and the first access networkdevice based on the first QoS parameter and a second QoS parameter thatis between a terminal device and the first UPF network element.

The second QoS parameter may also be referred to as an end-to-end QoSparameter between the terminal device and the UPF network element. Thesecond QoS parameter may include an end-to-end PDB between the terminaldevice and the UPF network element. The third QoS parameter may also bereferred to as a QoS parameter of an AN. The third QoS parameter mayinclude a PDB between the terminal device and the first access networkdevice, for example, an AN PDB.

For example, the control plane network element subtracts the first QoSparameter from the second QoS parameter, to obtain the third QoSparameter.

Step 1603: The control plane network element sends the third QoSparameter to the first access network device. Correspondingly, the firstaccess network device receives the third QoS parameter from the controlplane network element.

For example, the control plane network element may send the third QoSparameter to the first access network device using N2 session managementinformation (N2 SM info).

Step 1604: The first access network device schedules an air interfaceresource between the terminal device and the first access network devicebased on the third QoS parameter.

Therefore, compared with that, in the other approaches, the first accessnetwork device performs air interface resource scheduling based on anend-to-end QoS parameter between UE and a UPF, in the method accordingto this embodiment of this application, the first access network devicemay perform air interface resource scheduling based on a more preciseQoS parameter, namely, a QoS parameter between the UE and an AN,optimizing usage of an air interface resource.

FIG. 16B is a schematic flowchart of a QoS parameter processing methodaccording to an embodiment of this application. A difference betweenFIG. 16B and FIG. 16A lies in that, in the method shown in FIG. 16A, thecontrol plane network element determines the QoS parameter between theUE and the AN. However, in the method shown in FIG. 16B, a first accessnetwork device determines a QoS parameter between UE and an AN. As shownin FIG. 16B, this method includes the following steps.

Step 1611: A control plane network element obtains a first QoS parameterbetween the first access network device and a first UPF network element.

For step 1611, refer to the description of step 1601. Details are notdescribed herein again.

Step 1612: The control plane network element sends the first QoSparameter to the first access network device, where the first QoSparameter is used to determine a QoS parameter between a terminal deviceand the first access network device. Correspondingly, the first accessnetwork device receives the first QoS parameter from the control planenetwork element.

Similarly, the control plane network element may send the first QoSparameter to the first access network device using N2 SM info.

Step 1613: The first access network device determines a third QoSparameter between the terminal device and the first access networkdevice based on the first QoS parameter and a second QoS parameter thatis between the terminal device and the first UPF network element.

For example, the first access network device subtracts the first QoSparameter from the second QoS parameter, to obtain the third QoSparameter.

Step 1604: The first access network device schedules an air interfaceresource between the terminal device and the first access network devicebased on the third QoS parameter.

Similarly, compared with that, in the other approaches, the first accessnetwork device performs air interface resource scheduling based on anend-to-end QoS parameter between UE and a UPF, in the method accordingto this embodiment of this application, the first access network devicemay perform air interface resource scheduling based on a more preciseQoS parameter, namely, a QoS parameter between the UE and an AN,optimizing usage of an air interface resource.

In examples in FIG. 17 to FIG. 23, descriptions are provided using anexample in which a QoS parameter is a PDB. That is, the first QoSparameter is a CN PDB, the second QoS parameter is an end-to-end PDB,and the third QoS parameter is an AN PDB.

FIG. 17 is a signaling interaction diagram of processing a QoS parameteraccording to an embodiment of this application. As shown in FIG. 17,this method includes the following steps.

Step 1701: UE initiates a PDU session establishment procedure. The UEsends a PDU session establishment request message to an access andmobility management function (AMF) network element.

The PDU session establishment request message includes at least a PDUsession identifier (ID).

Step 1702: The AMF network element selects an SMF network element, andthe SMF network element selects a PCF network element and a UPF networkelement.

Optionally, the SMF network element obtains subscription data of the UEfrom a UDM network element.

Step 1703: The SMF network element obtains a policy and charging control(PCC) policy from the PCF network element by interacting with the PCFnetwork element. The PCC policy includes a 5G QoS indicator (5QI), orthe SMF may generate a 5G QoS indicator based on the PCC policy.

Step 1704: The SMF network element initiates an N4 session establishmentprocess.

For example, the SMF network element sends an N4 session establishmentrequest message to the UPF network element. The N4 session establishmentrequest message includes identifier information of a RAN device, torequest the UPF network element to return a CN PDB between the RANdevice and the UPF network element. For example, the identifierinformation of the RAN device includes an IP address of the RAN device.Optionally, the N4 session establishment request message furtherincludes indication information, and the indication informationindicates the UPF network element to return the CN PDB between the RANdevice and the UPF network element.

Optionally, the N4 session establishment request message furtherincludes flow information that identifies a first flow. For example, thefirst flow is a QoS flow, and the flow information that identifies thefirst flow is a 5QI or a QFI. In this way, using the N4 sessionestablishment request message, the SMF network element requests the UPFnetwork element to return a CN PDB that is between the RAN device andthe UPF network element and that corresponds to the first flow.

Optionally, before the SMF network element sends the N4 sessionestablishment request message to the UPF network element, the SMFnetwork element first searches the SMF network for the CN PDB betweenthe RAN device and the UPF network element or the CN PDB that is betweenthe RAN device and the UPF network element and that corresponds to thefirst flow. The SMF network element sends the N4 session establishmentrequest message including identifier information of a RAN networkelement to the UPF network element only if the CN PDB does not exist inthe SMF network element. If the SMF network element stores the CN PDB,the SMF may directly determine the CN PDB between the RAN device and theUPF network element or the CN PDB that is between the RAN device and theUPF network element and that corresponds to the first flow. The N4session establishment request message may not carry the identifierinformation of the RAN device, or steps 1704 and 1705 may be skipped.

Step 1705: After receiving the N4 session establishment request message,the UPF network element returns the CN PDB to the SMF network elementusing an N4 session establishment response message. Optionally, if theN4 session establishment request message further includes the flowinformation that identifies the first flow, the returned CN PDB is theCN PDB that is between the RAN device and the UPF network element andthat corresponds to the first flow.

For example, a CN PDB between the UPF and each RAN device ispre-configured in the UPF. For example, the network management systemmay obtain topology information (for example, a transmission distance)between the RAN and the UPF, generate the CN PDN between the RAN deviceand the UPF network element based on the topology information, andconfigure the CN PDN for each UPF network element in a power-on phase.Alternatively, the UPF network element may obtain a CN PDB in a QoSmonitoring result through QoS monitoring.

After receiving the N4 session establishment request message, the UPFnetwork element determines the CN PDB between the UPF network elementand the RAN device based on the identifier information of the RANdevice, and sends the CN PDB to the SMF network element.

Optionally, after receiving the CN PDB, the SMF network element maystore the received CN PDB. In this way, for different QoS flows thatsubsequently come from a same RAN device, if the SMF network elementselects a same UPF network element, the SMF network element may directlyreuse the stored CN PDB without requesting the UPF network element.

After receiving the CN PDB, the SMF network element may perform steps inany one of the following implementations: a first implementationcorresponding to steps 1706 and 1707, and a second implementationcorresponding to steps 1708 and 1709.

In the first implementation:

Step 1706: The SMF network element determines an AN PDB based on the CNPDB and an end-to-end PDB between the UE and the UPF network element.

For example, the SMF network element obtains the end-to-end PDB betweenthe UE and the UPF network element according to the 5QI. If the 5QI is astandard value, the SMF network element may obtain the PDB between theUE and the UPF network element according to the 5QI. If the 5QI is not astandard value, the SMF network element may obtain the PDB between theUE and the UPF network element from a QoS profile corresponding to theQFI. Then, the SMF network element subtracts the CN PDB from theend-to-end PDB between the UE and the UPF network element, to obtain theAN PDB.

It should be noted that the CN PDB is a PDB between the RAN networkelement and the UPF network element, and usually may be unrelated to the5QI. That is, for different 5QIs, there is no difference between CNPDBs. However, because there is a reserved bit in a protocol, the UPFnetwork element may alternatively set a differentiated services codepoint (DSCP) in an outer IP header of a data packet according to the5QI, to perform differentiated transmission. This causes a differencebetween CN PDBs. Therefore, in the present disclosure, a CN PDB may bedifferent based on a different 5QI or QFI, to be specific, in step 1704,the SMF network element requests the UPF network element to return theCN PDB that is between the RAN device and the UPF network element andthat corresponds to the first flow.

However, regardless of whether the CN PDB is related to the flowinformation, the determined AN PDB is associated with (or has a bindingrelationship to) the 5QI (or the QFI), and different 5QIs (or QFIs)correspond to different AN PDBs.

Step 1707: The SMF network element sends the AN PDB to the RAN device.

For example, the SMF network element sends a PDU session ID and N2 SMinformation to the AMF network element by invoking a communicationsservice Namf_Communication_N1N2MessageTransfer of the AMF networkelement or by invoking a session management context update serviceNsmf_PDUSession_UpdateSMContext of the SMF network element. The N2 SMinformation includes the PDU session ID, a QFI, and the AN PDB. Forexample, the AN PDB is included in a QoS profile corresponding to theQFI. The AMF network element sends the received N2 SM information to theRAN device. Correspondingly, the RAN device receives the AN PDB includedin the N2 SM information.

In a second implementation:

Step 1708: The SMF network element sends the CN PDB to the RAN device.

Similarly, the SMF network element sends a PDU session ID and N2 SMinformation to the AMF network element by invoking a communicationsservice Namf_Communication_N1N2MessageTransfer of the AMF networkelement or by invoking a session management context update serviceNsmf_PDUSession_UpdateSMContext of the SMF network element. The N2 SMinformation includes the PDU session ID and the CN PDB. For example, theCN PDB is included in a QoS profile corresponding to each QFI. The AMFnetwork element sends the received N2 SM information to the RAN device.Correspondingly, the RAN device receives the CN PDB included in the N2SM information.

It should be noted that the QoS profile itself includes the 5QI. Herein,if the CN PDB is on a device granularity, that is, the CN PDB isunrelated to the 5QI, the 5QI may not need to be associated when the CNPDB is sent. If the CN PDB is on a flow granularity, that is, the CN PDBis related to the 5QI, different 5QIs have different CN PDBs, and a 5QIneeds to be provided at the same time when a CN PDB is provided. In thisapplication, if the CN PDB is included in the QoS profile, because theQoS profile includes the 5QI, a relationship between the CN PDB and the5QI does not need to be additionally bound. If the CN PDB is included ina part that is not the QoS profile in the N2 SM information, a 5QIassociated with the CN PDB needs to be provided.

Step 1709: The RAN device determines an AN PDB based on the CN PDB andan end-to-end PDB between the UE and the UPF network element.

For example, the RAN device obtains the end-to-end PDB between the UEand the UPF network element according to the 5QI. If the 5QI is astandard value, the RAN device may obtain the PDB between the UE and theUPF network element according to the 5QI. If the 5QI is not a standardvalue, the RAN device may obtain the PDB between the UE and the UPFnetwork element from a QoS profile that corresponds to the QFI and thatis delivered by a core network. Then, the RAN device subtracts the CNPDB from the end-to-end PDB between the UE and the UPF network element,to obtain the AN PDB.

For any one of the foregoing implementations, after an AN obtains the ANPDB, step 1710 is performed.

Step 1710: The RAN device schedules an air interface resource of the UEand the RAN device based on the AN PDB.

As described above, because the AN PDB is associated with the 5QI (orthe QFI), the RAN device schedules, based on the AN PDB associated withthe 5QI (or the QFI), the air interface resource for a QoS flowcorresponding to the 5QI (or the QFI).

After step 1710, remaining steps of the PDU session establishmentprocedure may continue to be performed, and include but are not limitedto the following. The RAN device interacts with the UE to complete airinterface configuration, and the RAN device interacts with the AMFnetwork element, and the AMF network element interacts with the SMFnetwork element to complete updating of a PDU session managementcontext, and complete the session establishment procedure.

FIG. 18A and FIG. 18B are another signaling interaction diagram ofprocessing a QoS parameter according to an embodiment of thisapplication. FIG. 18A and FIG. 18B are described with reference to FIG.17. As shown in FIG. 18A and FIG. 18B, this method includes thefollowing steps.

Step 1801: UE initiates a PDU session establishment procedure. The UEsends a PDU session establishment request message to an AMF networkelement.

For example, the UE sends a non-access stratum (NAS) message to the AMFnetwork element. The NAS message includes single-network slice selectionassistance information (S-NSSAI) and the PDU session establishmentrequest message. The PDU session establishment request message includesat least an ID of a PDU session.

Step 1802: The AMF network element selects an SMF network element, andthe SMF network element selects a PCF network element.

Then, a step in any one of the following implementations may beperformed a first implementation corresponding to steps 1803 to 1805, asecond implementation corresponding to steps 1806 to 1808, and a thirdimplementation corresponding to 1809.

In the first implementation:

Step 1803: The SMF network element selects a UPF network element.

Step 1804: The SMF network element sends identifier information of theUPF network element and identifier information of a RAN device to an NRFnetwork element, to request the NRF network element to return a CN PDBbetween the RAN device and the UPF network element.

For example, the SMF network element may invoke a network functiondiscovery (Nnrf_NFDiscovery) service of the NRF network element, to senda network function discovery request (Nnrf_NFDiscovery_Request) messagethat includes the identifier information of the UPF network element andthe identifier information of the RAN device to the NRF network element.

Optionally, the SMF network element may first determine, based on theS-NSSAI carried in step 1801, that the session corresponds to a URLLCservice, and then request, from the NRF network element, the CN PDBbetween the RAN device and the UPF network element.

Step 1805: The NRF network element sends the CN PDB between the UPFnetwork element and the RAN device to the SMF network element.

In a second implementation:

Step 1806: The SMF network element sends the identifier information ofthe RAN device and service area information of the SMF network elementto the NRF network element, to request the NRF network element to returnidentifier information of at least one UPF network element located in anarea indicated by the service area information, and a CN PDB betweeneach of the at least one UPF network element and the RAN device.

Similarly, for example, the SMF network element may invoke the networkfunction discovery service of the NRF network element, to send, to theNRF network element, a network function discovery request message thatincludes the identifier information of the RAN device and the servicearea information of the SMF network element.

Similarly, optionally, the SMF network element may first determine,based on the S-NSSAI carried in step 1801, that the session correspondsto the URLLC service, and then send the identifier information of theRAN device and the service area information of the SMF to the NRFnetwork element.

Step 1807: The SMF network element receives, from the NRF networkelement, the identifier information of the at least one UPF networkelement located in the area indicated by the service area information,and a set of the CN PDB between each of the at least one UPF networkelement and the RAN device.

Step 1808: The SMF network element determines a CN PDB from the receivedCN PDB set, and selects a UPF network element.

Optionally, the SMF network element selects a CN PDB with a smallestvalue from the received CN PDB set as the CN PDB, and selects acorresponding UPF network element. Therefore, as many resources aspossible may be reserved for a RAN side, to reduce pressure on an airinterface resource.

For example, the service area of the SMF network element includes a UPF1 and a UPF 2. In step 1807, the CN PDB set received by the SMF networkelement includes a CN PDB 1 of (UPF 1, RAN 1) and a CN PDB 2 of (UPF 2,RAN 1). A value of the CN PDB 1 is less than a value of the CN PDB 2. Inthis case, the SMF selects the CN PDB 1 from the CN PDB set as thedetermined CN PDB, and correspondingly selects the UPF 1 networkelement.

In a third implementation:

The SMF network element stores a set of a CN PDB between each UPFnetwork element and each RAN device that are in the SMF service area.

For example, when the SMF network element is powered on, the SMF networkelement sends the service area information of the SMF network element tothe NRF network element. After receiving the service area information ofthe SMF network element, the NRF network element returns, to the SMFnetwork element, identifier information of each UPF network elementlocated in the SMF service area, identifier information of each RANdevice located in the SMF service area, and a respective CN PDB betweenthe UPF network element and the RAN device. Therefore, the SMF networkelement stores the set of the CN PDB between each UPF network elementand each RAN device that are in the SMF service area.

Step 1809: The SMF network element determines a CN PDB from the storedCN PDB set based on the identifier information of the RAN device, andselects a UPF network element.

Optionally, the SMF network element selects a CN PDB with a smallestvalue from the stored CN PDB set as the CN PDB based on the identifierinformation of the RAN device, and selects a corresponding UPF networkelement. Therefore, as many resources as possible may be reserved for aRAN side, to reduce pressure on an air interface resource.

For example, in step 1809, the CN PDB set stored in the SMF networkelement includes a CN PDB 1 of (UPF 1, RAN 1), a CN PDB 2 of (UPF 1, RAN2), a CN PDB 3 of (UPF 2, RAN 1), and a CN PDB 4 of (UPF 2, RAN 3). Avalue of the CN PDB 1 is less than a value of the CN PDB 3. In a sessionestablishment process, it is assumed that the identifier information ofthe RAN device corresponds to the RAN 1. The SMF network element selectsthe CN PDB 1 with a smaller CN PDB value based on values of the CN PDB 1and the CN PDB 3, and selects the corresponding UPF 1.

In any one of the foregoing implementations, the identifier informationof the UPF network element may include an IP address of the UPF networkelement. The identifier information of the RAN device may include an IPaddress of the RAN device.

For any one of the foregoing implementations, after the SMF networkelement obtains the CN PDB, step 1810 is performed.

Step 1810: The SMF network element obtains a PCC policy from the PCFnetwork element by interacting with the PCF network element. The PCCpolicy includes a 5QI.

Optionally, the SMF network element further initiates an N4 sessionestablishment process (not shown in the figure) to the UPF networkelement.

Then, steps 1811 and 1812 or steps 1813 and 1814 may be performed. Then,step 1815 may be performed.

For steps 1811 to 1815, refer to the descriptions of steps 1706 to 1710in FIG. 17. Details are not described herein again.

FIG. 19 is still another signaling interaction diagram of processing aQoS parameter according to an embodiment of this application. FIG. 19 isdescribed with reference to FIG. 17 and FIG. 18A and FIG. 18B.

In an example in FIG. 19, a network management system pre-configures, onan SMF network element, a set of a CN PDB between each UPF networkelement and each RAN device that are in an SMF service area.

For example, when the SMF network element is powered on, the networkmanagement system configures, for the SMF network element, identifierinformation of each UPF network element located in the SMF service area,identifier information of each RAN device located in the SMF servicearea, and a respective CN PDB between the UPF network element and theRAN device. Alternatively, after the SMF network element is powered on,the SMF network element actively sends a request to the networkmanagement system, to request to obtain the identifier information ofeach UPF network element located in the SMF service area, the identifierinformation of each RAN device located in the SMF service area, and therespective CN PDB between the UPF network element and the RAN device.

As shown in FIG. 19, this method includes the following steps.

For steps 1901 and 1902, refer to the descriptions of steps 1801 and1802 in FIG. 18A and FIG. 18B. Details are not described herein again.

For step 1903, refer to the description of step 1809 in FIG. 18A andFIG. 18B. A difference lies in that: in the example of FIG. 18A and FIG.18B, the CN PDB set is configured for the SMF network element by the NRFnetwork element. In the example in FIG. 19, the CN PDB set is configuredfor the SMF network element by the network management system.

For step 1904, refer to the description of step 1810 in FIG. 18A andFIG. 18B. Details are not described herein again.

Optionally, the SMF network element further initiates an N4 sessionestablishment process (not shown in the figure) to the UPF networkelement.

Then, steps 1905 and 1906 or steps 1907 and 1908 may be performed. Then,step 1909 may be performed.

For steps 1905 to 1909, refer to the descriptions of steps 1706 to 1710in FIG. 17. Details are not described herein again.

A QoS parameter may be divided in a session establishment process, or aQoS parameter may be divided in a session modification process, or a QoSparameter may be divided in a service request process. Details are notdescribed herein.

In addition, a QoS parameter may alternatively be divided in a handoverprocess. The following provides descriptions using an example in whichan SMF network element obtains a CN PDB from a UPF network element.However, a QoS parameter may alternatively be divided in a handoverprocess in a manner of obtaining the CN PDB from the NRF network elementin FIG. 18A and FIG. 18B, or configuring the CN PDB in the SMF networkelement by the network management system in FIG. 19.

For example, a QoS parameter may be divided and delivered in a handoverpreparation phase. FIG. 20 is a signaling interaction diagram of a QoSparameter processing method performed based on Xn handover. FIG. 21 is asignaling interaction diagram of a QoS parameter processing methodperformed based on N2 handover. The Xn handover means that UE handoveris performed based on an Xn interface between a source RAN device and atarget RAN device. The N2 handover means that UE handover is performedbased on an N2 interface between an AMF network element and a RAN device(for example, when there is no Xn interface between the source RANdevice and the target RAN device).

As shown in FIG. 20, this method includes the following steps.

Step 2001: After making a handover decision, the source RAN device sendsa handover request message to the target RAN device. The handoverrequest message includes an ID of a to-be-handed-over PDU session.

Step 2002: The target RAN device sends a request message to an SMFnetwork element. For example, the handover request message is a handoverrequired message. The request message includes the ID of theto-be-handed-over PDU session.

Step 2003: The SMF network element selects an intermediate UPF networkelement.

This step is an optional step.

Step 2004: The SMF network element initiates an N4 session modificationprocess.

For example, the SMF network element sends an N4 session modificationrequest message to an anchor UPF network element. The N4 sessionmodification request message includes identifier information of thetarget RAN device, to request the UPF network element to return a CN PDBbetween the target RAN device and the anchor UPF network element.Optionally, the N4 session modification request message further includesindication information, and the indication information indicates the UPFnetwork element to return the CN PDB between the target RAN device andthe anchor UPF network element.

Optionally, the N4 session modification request message further includesflow information that identifies a first flow. For example, the firstflow is a QoS flow, and the flow information is a 5QI or a QFI. In thisway, using the N4 session modification request message, the SMF networkelement requests the UPF network element to return a CN PDB that isbetween the target RAN device and the anchor UPF network element andthat corresponds to the first flow.

Optionally, before the SMF network element sends the N4 sessionmodification request message to the UPF network element, the SMF networkelement first searches the SMF network element for the CN PDB betweenthe target RAN device and the anchor UPF network element. The SMFnetwork element sends the N4 session modification request messageincluding the identifier information of the target RAN device to the UPFnetwork element only if no CN PDB between the target RAN device and theanchor UPF network element exists in the SMF network element. If the SMFnetwork element stores the CN PDB between the target RAN device and theanchor UPF network element, the SMF may directly determine the CN PDBbetween the target RAN device and the anchor UPF network element. The N4session modification request message may not carry the identifierinformation of the target RAN device, or steps 2004 and 2005 may beskipped.

Step 2005: After receiving the N4 session modification request message,the UPF network element returns the CN PDB to the SMF network elementusing an N4 session modification answer message. Optionally, if the N4session establishment request message further includes the flowinformation that identifies the first flow, the returned CN PDB is theCN PDB that is between the target RAN device and the anchor UPF networkelement and that corresponds to the first flow.

Step 2006: The SMF network element sends a handover response message tothe target RAN device. In an implementation, the SMF network elementdetermines an AN PDB based on the CN PDB and the 5QI, and sends, via theAMF network element, the handover response message including the AN PDBto the target RAN device. For how the SMF network element determines theAN PDB based on the CN PDB and the 5QI, refer to the description of step1706. Details are not described herein again. In addition, the handoverresponse message further includes the ID of the to-be-handed-over PDUsession and flow information (a QFI or a 5QI) corresponding to the ANPDB.

In another implementation, the SMF network element sends, via the AMFnetwork element, a handover response message including the CN PDB to thetarget RAN device. In addition, the handover response message furtherincludes the ID of the to-be-handed-over PDU session. Optionally, thehandover response message further includes flow information (a QFI or a5QI) corresponding to the AN PDB. After receiving the handover responsemessage, the target RAN device determines the AN PDB based on the CN PDBand the 5QI. For how the target RAN device determines the AN PDB basedon the CN PDB and the 5QI, refer to the description of step 1709.Details are not described herein again.

Step 2007: The target RAN device performs admission control.

For example, the target RAN device determines, based on the AN PDB andthe 5QI, whether to allow a QoS flow corresponding to the QFI to beswitched, to determine an accepted QoS flow list. For example, thetarget RAN device obtains a corresponding QoS requirement (a packet lossrate requirement) based on the 5QI, obtains a corresponding latencyrequirement based on the AN PDB, and may further determine, based onparameters in a QoS profile, such as a guaranteed flow bit rate (GFBR),a maximum flow bit rate (MFBR), and a priority, a PDU session that isallowed to be handed over and that can satisfy the foregoing latency,bandwidth, and packet loss rate requirements, and a QoS flow that isallowed to be switched in the PDU session that is allowed to be handedover.

Step 2008: The target RAN device sends a handover requestacknowledgement (ACK) message to the source RAN device.

Then, a remaining handover procedure, such as respective steps of ahandover execution phase and a handover complete phase, may beperformed.

After the handover is completed, the target RAN device schedules an airinterface resource based on the AN PDB.

That is, the target RAN device allocates a radio resource to acorresponding QoS flow based on an AN PDB corresponding to the QFI.

In step 2004 and step 2005 in this embodiment, the manner 1 in which“the control plane network element obtains the first QoS parameter fromthe first UPF network element” in steps 1601 to 1611 is used as anexample, and the method for obtaining the first QoS parameter by the SMFdescribed in the manner 2, the manner 3, or the manner 4 in steps 1601to 1611 may also be supported. Details are not described herein again.

The method shown in FIG. 21 includes the following steps.

Step 2101: After determining to trigger handover, the source RAN devicesends a handover request (handover required) message to an AMF networkelement, where the handover request message includes identifierinformation of the target RAN device and an identifier of ato-be-handed-over PDU session.

Step 2102: The AMF network element requests an SMF network elementcorresponding to the to-be-handed-over PDU session to update a contextof the UE.

For example, the AMF network element may invoke an SM context update(Nsmf_PDUSession_UpdateSMContext) service of the SMF network element, tosend a UE context update request message to the SMF network element. TheUE context update request message includes identifier information of thetarget RAN device.

Step 2103: The SMF network element initiates an N4 session modificationprocedure, and sends an N4 session modification request messageincluding the identifier information of the target RAN device to ananchor UPF network element, to request the UPF network element to returna CN PDB between the target RAN device and the anchor UPF networkelement.

Step 2104: After receiving the N4 session modification request message,the UPF network element returns the CN PDB to the SMF network elementusing an N4 session modification answer message.

For steps 2103 and 2104, refer to the descriptions of steps 2004 and2005. Details are not described herein again.

Step 2105: The SMF network element returns a UE context update responsemessage to the AMF network element.

In an implementation, the SMF network element determines an AN PDB basedon the CN PDB and a 5QI, and sends a context update response messageincluding the AN PDB to the AMF network element. For how the SMF networkelement determines the AN PDB based on the CN PDB and the 5QI, refer tothe description of step 1706. Details are not described herein again. Inaddition, the context update response message further includes the ID ofthe to-be-handed-over PDU session and flow information (a QFI or a 5QI)corresponding to the AN PDB.

In another implementation, the SMF network element sends a contextupdate response message including the CN PDB to the AMF network element.In addition, the context update response message further includes the IDof the to-be-handed-over PDU session. Optionally, the context updateresponse message further includes flow information (a QFI or a 5QI)corresponding to an AN PDB.

Step 2106: The AMF network element manages a UE context update responsemessage from each SMF network element corresponding to theto-be-handed-over PDU session.

Step 2107: The AMF network element sends the received AN PDB or CN PDBto the target RAN device using a handover request message.

If receiving the CN PDB, the target RAN device determines the AN PDBbased on the CN PDB and a 5QI. For how the target RAN device determinesthe AN PDB based on the CN PDB and the 5QI, refer to the description ofstep 1709. Details are not described herein again.

Step 2108: The target RAN device performs admission control.

For step 2108, refer to the description of step 2007. Details are notdescribed herein again.

Step 2109: The target RAN device sends a handover request ACK message tothe AMF network element.

Then, a remaining handover procedure, such as respective steps of ahandover execution phase and a handover complete phase, may beperformed.

After the handover is completed, the target RAN device schedules an airinterface resource based on the AN PDB.

Similarly, in step 2103 and step 2104 in this embodiment, the manner 1in which “the control plane network element obtains the first QoSparameter from the first UPF network element” in steps 1601 to 1611 isused as an example, and the method for obtaining the first QoS parameterby the SMF described in the manner 2, the manner 3, or the manner 4 insteps 1601 to 1611 may also be supported. Details are not describedherein again.

In addition to a handover preparation phase, a QoS parameter may bedivided and delivered in a handover completion phase. Processingperformed in the handover completion phase applies to both Xn and N2handovers. FIG. 22 is described using Xn handover as an example.

The method shown in FIG. 22 includes the following steps.

After air interface handover is completed, that is, after handoverexecution is completed, a handover completion phase is entered. In thehandover completion phase, a source RAN device forwards receiveddownlink data to a target RAN device, and finally sends the downlinkdata to UE.

Step 2201: The target RAN device sends an N2 path switch request messageto an AMF network element.

It should be noted that, in an N2 handover scenario, in step 2201, thetarget RAN device sends a handover notify message to the AMF networkelement.

Step 2202: The AMF network element requests an SMF network elementcorresponding to a to-be-handed-over PDU session to update a context ofthe UE.

For example, the AMF network element may invoke an SM context update(Nsmf_PDUSession_UpdateSMContext) service of the SMF network element, tosend a UE context update request message to the SMF network element. TheUE context update request message includes identifier information of thetarget RAN device.

Step 2203: The SMF network element initiates an N4 session modificationprocedure, and sends an N4 session modification request messageincluding the identifier information of the target RAN device to ananchor UPF network element, to request the UPF network element to returna CN PDB between the target RAN device and the anchor UPF networkelement.

Step 2204: After receiving the N4 session modification request message,the UPF network element returns the CN PDB to the SMF network elementusing an N4 session modification answer message.

For steps 2203 and 2204, refer to the descriptions of steps 2004 and2005. Details are not described herein again.

Step 2205: The SMF network element returns a UE context update responsemessage to the AMF network element.

In an implementation, the SMF network element determines an AN PDB basedon the CN PDB and a 5QI, and sends a context update response messageincluding the AN PDB to the AMF network element. For how the SMF networkelement determines the AN PDB based on the CN PDB and the 5QI, refer tothe description of step 1706. Details are not described herein again. Inaddition, the context update response message further includes the ID ofthe to-be-handed-over PDU session and flow information (a QFI or a 5QI)corresponding to the AN PDB.

In another implementation, the SMF network element sends a contextupdate response message including the CN PDB to the AMF network element.In addition, the context update response message further includes the IDof the to-be-handed-over PDU session. Optionally, the context updateresponse message further includes flow information (a QFI or a 5QI)corresponding to the CN PDB.

Step 2206: The AMF network element sends the received AN PDB or CN PDBto the target RAN device using an N2 path switch request ACK message.

If receiving the CN PDB, the target RAN device determines the AN PDBbased on the CN PDB and a 5QI. For how the target RAN device determinesthe AN PDB based on the CN PDB and the 5QI, refer to the description ofstep 1709. Details are not described herein again.

Step 2207: The target RAN device determines, based on the AN PDB and the5QI, whether to allow a QoS flow corresponding to the QFI to beswitched, to determine an accepted QoS flow list. For example, thetarget RAN device obtains a corresponding QoS requirement (a packet lossrate requirement) based on the 5QI, obtains a corresponding latencyrequirement based on the AN PDB, and may further determine, based onparameters in a QoS profile, such as a GFBR, an MFBR, and a priority, aPDU session that is allowed to be handed over and that can satisfy theforegoing latency, bandwidth, and packet loss rate requirements, and aQoS flow that is allowed to be switched in the PDU session that isallowed to be handed over.

Step 2208: The target RAN device sends a resource release message to thesource RAN device, to acknowledge that handover succeeds.

After the handover is completed, the target RAN device schedules an airinterface resource based on the AN PDB.

That is, the target RAN device allocates a radio resource to acorresponding QoS flow based on an AN PDB corresponding to the QFI.

Similarly, in step 2203 and step 2204 in this embodiment, the manner 1in which “the control plane network element obtains the first QoSparameter from the first UPF network element” in steps 1601 to 1611 isused as an example, and the method for obtaining the first QoS parameterby the SMF described in the manner 2, the manner 3, or the manner 4 insteps 1601 to 1611 may also be supported. Details are not describedherein again.

Therefore, with reference to the foregoing descriptions of FIG. 20 toFIG. 22, the method shown in FIG. 16A or FIG. 16B may alternatively beperformed in a handover procedure. In this scenario, a first accessnetwork device is the target RAN device that serves the UE afterhandover. Therefore, performing the foregoing method in the handoverprocedure enables an AN PDB of a QoS flow in the to-be-handed-over PDUsession to be determined such that the target RAN device can performadmission control of the QoS flow based on the AN PDB, and perform airinterface resource scheduling after handover based on the AN PDB,thereby optimizing usage of the air interface resource.

FIG. 23 further provides a schematic flowchart of a QoS parameterprocessing method in a handover phase. The method is applicable to Xnhandover and is performed in a handover preparation phase. FIG. 23 isdescribed with reference to FIG. 20. A difference between the methodshown in FIG. 23 and the method shown in FIG. 20 lies in that: in FIG.20, the target RAN device requests, from the SMF network element, the CNPDB between the target RAN device and the anchor UPF network element, inFIG. 23, a source RAN device requests, from an SMF network element, a CNPDB between a target RAN device and an anchor UPF network element.

The method shown in FIG. 23 includes the following steps.

Step 2301: After making a handover decision, the source RAN device sendsidentifier information of the target RAN device and an ID of ato-be-handed-over PDU session to the SMF network element via an AMFnetwork element.

Step 2302: The SMF network element initiates an N4 session modificationprocess, and sends an N4 session modification request message includingthe identifier information of the target RAN device to an anchor UPFnetwork element, to request the UPF network element to return a CN PDBbetween the target RAN device and the anchor UPF network element.

Step 2303: After receiving the N4 session modification request message,the UPF network element returns the CN PDB to the SMF network elementusing an N4 session modification answer message.

For steps 2302 and 2303, refer to the descriptions of steps 2004 and2005. Details are not described herein again.

Step 2304: The SMF network element sends the CN PDB or an AN PDB to thesource RAN device via the AMF network element.

For example, in an implementation, the SMF network element determines anAN PDB based on the CN PDB and a 5QI, and sends, via the AMF networkelement, a message including the AN PDB to the source RAN device. Forhow the SMF network element determines the AN PDB based on the CN PDBand the 5QI, refer to the description of step 1706. Details are notdescribed herein again. In addition, the message further includes the IDof the to-be-handed-over PDU session and flow information (a QFI or a5QI) corresponding to the AN PDB.

In another implementation, the SMF network element sends, via the AMFnetwork element, a message including the CN PDB to the source RANdevice. In addition, the message further includes the ID of theto-be-handed-over PDU session. Optionally, the message further includesflow information (a QFI or a 5QI) corresponding to the AN PDB.

Step 2305: The source RAN device sends a handover request message to thetarget RAN device. Based on the message received by the source RANdevice from the SMF network element, the handover request messageincludes the AN PDB or the CN PDB.

For example, the source RAN device updates a QoS profile of a QoS flowrelated to the to-be-handed over PDU session, and the updated QoSprofile includes the AN PDB or the CN PDB. The source RAN device sendsthe updated QoS profile to the target RAN device.

When the QoS profile includes the AN PDB, the target RAN device mayobtain the AN PDB from the QoS profile after receiving the QoS profile.When the QoS profile includes the CN PDB, the target RAN devicedetermines the AN PDB based on the CN PDB and the 5QI. For how thetarget RAN device determines the AN PDB based on the CN PDB and the 5QI,refer to the description of step 1709. Details are not described hereinagain.

Step 2306: The target RAN device performs admission control.

For step 2306, refer to the description of step 2007. Details are notdescribed herein again.

Step 2307: The target RAN device sends a handover request ACK message tothe source RAN device.

Then, a remaining handover procedure, such as respective steps of ahandover execution phase and a handover completion phase, may beperformed.

After the handover is completed, the target RAN device schedules an airinterface resource based on the AN PDB.

Similarly, in step 2302 and step 2303 in this embodiment, the manner 1in which “the control plane network element obtains the first QoSparameter from the first UPF network element” in steps 1601 to 1611 isused as an example, and the method for obtaining the first QoS parameterby the SMF described in the manner 2, the manner 3, or the manner 4 insteps 1601 to 1611 may also be supported. Details are not describedherein again.

Therefore, based on the description of FIG. 23, in an Xn handoverscenario, a first access network device is the target RAN device thatserves the UE after handover, and a second access network device is thesource RAN device that serves the UE before handover. Steps 1603 and1604 in FIG. 16A may be replaced with the following. The control planenetwork element sends a third QoS parameter to the second access networkdevice, the second access network device sends the third QoS parameterto the first access network device, and the first access network deviceschedules an air interface resource between the terminal device and thefirst access network device based on the third QoS parameter receivedfrom the second access network device. Similarly, steps 1612 to 1614 inFIG. 16B may be replaced with The control plane network element sendsthe first QoS parameter to the second access network device, the secondaccess network device sends the first QoS parameter to the first accessnetwork device, and the first access network device determines a thirdQoS parameter between the terminal device and the first access networkdevice based on the first QoS parameter received from the second accessnetwork device and a second QoS parameter between the terminal deviceand the first UPF network element, and schedules an air interfaceresource between the terminal device and the first access network devicebased on the third QoS parameter.

The following separately describes a control plane network element andan access network device that are configured to process a QoS parameter.

In an embodiment, the control plane network element 90 shown in FIG. 9may be further configured to implement a step performed by the controlplane network element in FIG. 16A or FIG. 16B, or a step performed bythe SMF network element in any one of FIG. 17 to FIG. 23.

For example, in an embodiment, the processing module 902 is configuredto obtain a first QoS parameter between a first access network deviceand a first UPF network element, and determine a third QoS parameterbetween a terminal device and the first access network device based onthe first QoS parameter and a second QoS parameter that is between theterminal device and the first UPF network element, and the transceivermodule 901 is configured to send the third QoS parameter to the firstaccess network device (or a second access network device in a handoverscenario).

In another embodiment, the processing module 902 is configured to obtaina first QoS parameter between a first access network device and a firstUPF network element, and the transceiver module 901 is configured tosend the first QoS parameter to the first access network device (or asecond access network device in a handover scenario). The first QoSparameter is used to determine a QoS parameter between a terminal deviceand the first access network device.

Therefore, compared with that, in the other approaches, the first accessnetwork device performs air interface resource scheduling based on anend-to-end QoS parameter between UE and a UPF, in the method accordingto this embodiment of this application, the first access network devicemay perform air interface resource scheduling based on a more preciseQoS parameter, namely, a QoS parameter between the UE and an AN,optimizing usage of an air interface resource. Optionally, theprocessing module 902 is configured to obtain the first QoS parameterfrom the first UPF network element, obtain the first QoS parameter froma network element discovery function device, obtain the first QoSparameter from a network management system, or obtain the first QoSparameter from a network data analytics function device.

Optionally, the processing module 902 controls the transceiver module901 to send identifier information of the first access network device tothe first UPF network element, and receive, from the first UPF networkelement, the first QoS parameter between the first access network deviceand the first UPF network element. Further, in a possible design, theprocessing module 902 controls the transceiver module 901 to send flowinformation that identifies a first flow to the first UPF networkelement. The first QoS parameter indicates a QoS parameter that isbetween the first access network device and the first UPF networkelement and that corresponds to the first flow.

In a possible design, the processing module 902 controls the transceivermodule 901 to send identifier information of the first access networkdevice and identifier information of the first UPF network element tothe network element discovery function device, and receive, from thenetwork element discovery function device, the first QoS parameterbetween the first access network device and the first UPF networkelement.

In another possible design, the processing module 902 controls thetransceiver module 901 to send identifier information of the firstaccess network device and service area information of the control planenetwork element to the network element discovery function device, andreceive, from the network element discovery function device, identifierinformation of at least one UPF network element located in an areaindicated by the service area information, and a QoS parameter betweeneach of the at least one UPF network element and the first accessnetwork device, where the processing module 902 is configured todetermine the first QoS parameter in the QoS parameter, or send servicearea information of the control plane network element to the networkelement discovery function device, and receive, from the network elementdiscovery function device, identifier information of at least one UPFnetwork element located in an area indicated by the service areainformation, identifier information of an access network device thatcommunicates with each of the at least one UPF network element, and aQoS parameter between each of the at least one UPF network element andthe access network device, where the processing module 902 is configuredto determine the first QoS parameter in the QoS parameter based onidentifier information of the first access network device.

With reference to the foregoing possible designs, further, theprocessing module 902 controls the transceiver module 901 to determinethe first UPF network element based on the QoS parameter that is betweeneach of the at least one UPF network element and the access networkdevice and that is received from the network element discovery functiondevice.

In addition, the communications apparatus shown in FIG. 10 may befurther configured to implement a step performed by the first accessnetwork device in FIG. 16A or FIG. 16B, or a step performed by the RANdevice in any one of FIG. 17 to FIG. 19, or a step performed by thetarget RAN device in any one of FIG. 20 to FIG. 23.

For example, the processing module 1002 is configured to obtain a QoSparameter between a terminal device and the first access network device,and schedule an air interface resource between the terminal device andthe first access network device based on the QoS parameter.

Therefore, compared with that, in the other approaches, the first accessnetwork device performs air interface resource scheduling based on anend-to-end QoS parameter between UE and a UPF, in the method accordingto this embodiment of this application, the first access network devicemay perform air interface resource scheduling based on a more preciseQoS parameter, namely, a QoS parameter between the UE and an AN,optimizing usage of an air interface resource.

In a possible design, the processing module 1002 is configured tocontrol the transceiver module 1001 to receive, from a control planenetwork element, a first QoS parameter between the first access networkdevice and a first UPF network element. The processing module 1002 isconfigured to determine the QoS parameter between the terminal deviceand the first access network device based on the first QoS parameter anda second QoS parameter that is between the terminal device and the firstUPF network element.

In another possible design, the processing module 1002 is configured tocontrol the transceiver module 1001 to receive the QoS parameter from acontrol plane network element.

In still another possible design, the processing module 1002 isconfigured to control the transceiver module 1001 to receive the QoSparameter from a second access network device. The first access networkdevice is a target access network device that serves the terminal deviceafter handover, and the second access network device is a source accessnetwork device that serves the terminal device before handover. In thiscase, the processing module 1002 is further configured to performhandover admission control on the terminal device based on the QoSparameter.

In addition, the communications apparatus shown in FIG. 10 may befurther configured to implement a step performed by the source RANdevice in any one of FIG. 20 to FIG. 23.

For example, in an embodiment, the processing module 1002 is configuredto control the transceiver module 1001 to receive, from a control planenetwork element, a first QoS parameter between the first access networkdevice and a first UPF network element. The processing module 1002 isconfigured to determine a third QoS parameter between a terminal deviceand the first access network device based on the first QoS parameter anda second QoS parameter that is between the terminal device and the firstUPF network element. The processing module 1002 is configured to controlthe transceiver module 1001 to send the third QoS parameter to the firstaccess network device.

In another embodiment, the processing module 1002 is configured tocontrol the transceiver module 1001 to receive a third QoS parameterbetween a terminal device and the first access network device from acontrol plane network element. The processing module 1002 is configuredto control the transceiver module 1001 to send the third QoS parameterto the first access network device.

The first access network device is a target access network device thatserves the terminal device after handover, and the second access networkdevice is a source access network device that serves the terminal devicebefore handover.

Therefore, compared with that, in the other approaches, the first accessnetwork device performs air interface resource scheduling based on theend-to-end QoS parameter between the UE and the UPF, in the methodaccording to this embodiment of this application, in a handoverscenario, the second access network device can receive the first QoSparameter or the third QoS parameter from the control plane networkelement, and then send the first QoS parameter or the third QoSparameter to the first access network device such that the first accessnetwork device may perform air interface resource scheduling based onthe more precise QoS parameter, namely, the QoS parameter between the UEand the AN, optimizing the usage of the air interface resource.

In addition, the memory 1503 in FIG. 15 stores program code that needsto be invoked when the processor 1502 performs the foregoing QoSparameter processing method performed by the control plane networkelement. Alternatively, a computer-readable storage medium 1504 storesprogram code that needs to be invoked when the control plane networkelement performs the foregoing QoS parameter processing method. Theprocessor 1502 in FIG. 15 can invoke the program code in the memory 1503or the computer-readable storage medium 1504, to perform an operationperformed by the control plane network element, the first access networkdevice, or the second access network device.

In the foregoing embodiments, the description of each embodiment hasrespective focuses. For a part that is not described in detail in anembodiment, refer to related descriptions in other embodiments.

It may be clearly understood by a person skilled in the art that, forthe purpose of convenient and brief description, for a detailed workingprocess of the foregoing system, apparatus, and module, refer to acorresponding process in the foregoing method embodiments, and detailsare not described herein again.

In the several embodiments provided in this application, it should beunderstood that the disclosed system, apparatus, and method may beimplemented in other manners. For example, the described apparatusembodiment is merely exemplary. For example, the module division ismerely logical function division and may be other division in actualimplementation. For example, a plurality of modules or components may becombined or integrated into another system, or some features may beignored or not performed. In addition, the displayed or discussed mutualcouplings or direct couplings or communication connections may beimplemented through some interfaces. The indirect couplings orcommunication connections between the apparatuses or modules may beimplemented in electronic, mechanical, or other forms.

In addition, functional modules in this application may be integratedinto one processing module, or each of the modules may exist alonephysically, or two or more modules are integrated into one module. Theintegrated module may be implemented in a form of hardware, or may beimplemented in a form of a software functional module. When theintegrated module is implemented in the form of a software functionalmodule and sold or used as an independent product, the integrated unitmay be stored in a computer-readable storage medium.

All or some of the foregoing embodiments may be implemented by means ofsoftware, hardware, firmware, or any combination thereof. When softwareis used to implement the embodiments, the embodiments may be implementedcompletely or partially in a form of a computer program product.

The computer program product includes one or more computer instructions.When the computer program instructions are loaded and executed on thecomputer, the procedure or functions according to the embodiments ofthis application are all or partially generated. The computer may be ageneral-purpose computer, a dedicated computer, a computer network, orother programmable apparatuses. The computer instructions may be storedin a computer-readable storage medium or may be transmitted from acomputer-readable storage medium to another computer-readable storagemedium. For example, the computer instructions may be transmitted from awebsite, computer, server, or data center to another website, computer,server, or data center in a wired (for example, a coaxial cable, anoptical fiber, or a digital subscriber line (DSL)) or wireless (forexample, infrared, radio, and microwave, and or the like) manner. Thecomputer-readable storage medium may be any usable medium accessible bya computer, or a data storage device, such as a server or a data center,integrating one or more usable media. The usable medium may be amagnetic medium (for example, a FLOPPY DISK, a hard disk, or a magnetictape), an optical medium (for example, a digital versatile disk (DVD)),a semiconductor medium (for example, a solid-state drive (SSD)), or thelike.

The technical solutions provided in this application are described indetail above. The principle and implementation of this application aredescribed herein through specific examples. The description about theembodiments is merely provided to help understand the method and coreideas of this application. In addition, persons of ordinary skill in theart can make variations and modifications to this application in termsof the specific implementations and application scopes according to theideas of this application. Therefore, the content of specification shallnot be construed as a limit to this application.

What is claimed is:
 1. A quality of service (QoS) parameter processingmethod comprising: obtaining, by a session management function device, acore network (CN) packet delay budget (PDB) between a first accessnetwork device and a first user plane function device, wherein the firstaccess network device is a target access network device serving aterminal device after a handover; sending, by the session managementfunction device, the CN PDB to the first access network device bysending a context update response message comprising the CN PDB to anaccess and mobility management function device to enable the access andmobility management function device to send an N2 path switch requestacknowledgement message comprising the CN PDB to the first accessnetwork device; receiving, by the first access network device, the CNPDB from the session management function device; determining, by thefirst access network device, an access network (AN) PDB between theterminal device and the first access network device based on the CN PDBand an end-to-end PDB between the terminal device and the first userplane function device; and scheduling, by the first access networkdevice, an air interface resource between the terminal device and thefirst access network device based on the AN PDB.
 2. The QoS parameterprocessing method of claim 1, wherein determining the AN PDB comprisessubtracting, by the first access network device, the CN PDB from theend-to-end PDB to obtain the AN PDB.
 3. The QoS parameter processingmethod of claim 1, wherein the CN PDB is associated with a first flow.4. The QoS parameter processing method of claim 1, wherein the contextupdate response message further comprises flow information correspondingto the CN PDB.
 5. The QoS parameter processing method of claim 4,wherein the flow information comprises a 5^(th) generation (5G) QoSindicator (5QI) or a QoS flow identifier (QFI).
 6. The QoS parameterprocessing method of claim 1, wherein obtaining the CN PDB comprises:obtaining, by the session management function device, the CN PDB fromthe first user plane function device; obtaining, by the sessionmanagement function device, the CN PDB from a device discovery functiondevice; obtaining, by the session management function device, the CN PDBfrom a network management system; or obtaining, by the sessionmanagement function device, the CN PDB from a network data analyticsfunction device.
 7. A system for processing a quality of service (QoS)parameter comprising: a first access network device; and a sessionmanagement function device coupled to the first access network deviceand configured to: obtain a core network (CN) packet delay budget (PDB)between the first access network device and a first user plane functiondevice, wherein the first access network device is a target accessnetwork device serving a terminal device after a handover; and send theCN PDB to the first access network device by sending a context updateresponse message comprising the CN PDB to an access and mobilitymanagement function device to enable the access and mobility managementfunction device to send an N2 path switch request acknowledgementmessage comprising the CN PDB to the first access network device,wherein the first access network device is configured to: receive the CNPDB from the session management function device; determine an accessnetwork (AN) PDB between the terminal device and the first accessnetwork device based on the CN PDB and an end-to-end PDB between theterminal device and the first user plane function device; and schedulean air interface resource between the terminal device and the firstaccess network device based on the AN PDB.
 8. The system of claim 7,wherein the first access network device is further configured tosubtract the CN PDB from the end-to-end PDB to obtain the AN PDB.
 9. Thesystem of claim 7, wherein the CN PDB is associated with a first flow.10. The system of claim 7, wherein the context update response messagefurther comprises flow information corresponding to the CN PDB.
 11. Thesystem of claim 10, wherein the flow information comprises a 5^(th)generation (5G) QoS indicator (5QI).
 12. The system of claim 11, whereinthe air interface resource is scheduled for a QoS data flowcorresponding to the 5QI.
 13. The system of claim 12, wherein the flowinformation further comprises at least one of a latency parameter, ajitter parameter, or a reliability parameter corresponding to the QoSdata flow.
 14. The system of claim 10, wherein the flow informationcomprises a QoS flow identifier (QFI).
 15. The system of claim 14,wherein the air interface resource is scheduled for a QoS data flowcorresponding to the QFI.
 16. The system of claim 10, wherein thecontext update response message further comprises an identifier ato-be-handed-over session and the flow information.
 17. The system ofclaim 7, wherein the session management function device is furtherconfigured to obtain the CN PDB from the first user plane functiondevice.
 18. The system of claim 7, wherein the session managementfunction device is further configured to obtain the CN PDB from a devicediscovery function device.
 19. The system of claim 7, wherein thesession management function device is further configured to obtain theCN PDB from a network management system.
 20. The system of claim 7,wherein the session management function device is further configured toobtain the CN PDB from a network data analytics function device.